Saturday

April 30, 2016
Number of results: 15,904

**Physics**

Two stones are thrown simultaneously, one straight upward from the base of a cliff and the other straight downward from the top of the cliff. The height of the cliff is 6.34 m. The stones are thrown with the same speed of 9.35 m/s. Find the location (above the base of the ...
*September 20, 2015 by Hannah*

**Physics **

Two stones are thrown simultaneously, one straight upward from the base of a cliff and the other straight downward from the top of the cliff. The height of the cliff is 6.41 m. The stones are thrown with the same speed of 8.35 m/s. Find the location (above the base of the ...
*October 1, 2015 by bob*

**Physics**

Two rollerbladers throw a frisbie back and forth on a frictionless surface. Which does not change? a. Momentum of an individual rollerblader b. Momentum of the frisbie c. Momentum of the system consisting of the frisbie and rollerbladers throwing the ball d. Momentum of the ...
*April 12, 2009 by Jacob*

**college Physics**

Two identical 0.18 kg blocks (labeled 1 and 2) are initially at rest on a nearly frictionless surface, connected by an unstretched spring, as shown in the upper diagram, where x2 = 0.06 m. Then a constant force of 9 N to the right is applied to block 2, and at a later time the...
*October 26, 2010 by Anonymous*

**Physics**

Just before landing on mars, a spaceshuttle turns on its retroengine and eventually comes to a complete stop 15 meters above the planets surface. It then drops freely down to the surface. How long does it take to fall to the surface.What is the impact speed? Is the answer 1.5 ...
*January 11, 2009 by Chloe*

**Physics**

Just before landing on mars, a spaceshuttle turns on its retroengine and eventually comes to a complete stop 15 meters above the planets surface. It then drops freely down to the surface. How long does it take to fall to the surface.What is the impact speed? Is the answer 1.5 ...
*January 11, 2009 by Chloe*

**Meteorology**

I have a skew t diagram and I need help with the following Temperature at the surface: Dewpoint at the surface: Winds near the surface: Temperature at 700 mb: Dewpoint at 700 mb:
*February 11, 2012 by Jessenia*

**Physics**

Select the motion diagram that corresponds to each of the four situations. E.g., if diag. A corresponds to the first situation, diag. C to the second, and none of the diagrams to situations 3 and 4, enter ACNN. Note that the velocity and acceleration vectors are shown; both ...
*September 29, 2015 by Michael *

**Physics**

A bowling ball of mass M and radius R is thrown along a level surface so that initially ( t= 0) it slides with a linear speed but does not rotate, see the figure. As it slides, it begins to spin, and eventually rolls without slipping. How far has the ball moved down the lane ...
*December 4, 2011 by Helen*

**Physics**

A bowling ball of mass M and radius R is thrown along a level surface so that initially ( t= 0) it slides with a linear speed but does not rotate, see the figure. As it slides, it begins to spin, and eventually rolls without slipping. How far has the ball moved down the lane ...
*December 4, 2011 by Helen*

**PHYSİCS I**

A mass m1 = 18.7 kg on a frictionless ramp is attached to a light string. The string passes over a frictionless pulley and is attached to a hanging mass m2. The ramp is at an angle of θ = 23.7° above the horizontal. m1 moves up the ramp uniformly (at constant speed). Find...
*March 1, 2012 by ADRİAANA*

**physics**

A mass m1 = 18.7 kg on a frictionless ramp is attached to a light string. The string passes over a frictionless pulley and is attached to a hanging mass m2. The ramp is at an angle of θ = 23.7° above the horizontal. m1 moves up the ramp uniformly (at constant speed). Find...
*March 2, 2012 by lissa*

**Physics**

Suppose a straight 1.25 mm diameter copper wire could just "float" horizontally in air because of the force of the Earth's magnetic field B, which is horizontal, perpendicular to the wire, and of magnitude 5.00 multiplied by 10-5 T. What current would the wire carry? I want to...
*February 10, 2011 by Justin*

**Physics**

A 0.30 kg puck, initially at rest on a frictionless horizontal surface, is struck by a 0.20 kg puck that is initially moving along the x axis with a velocity of 2.8 m/s. After the collision, the 0.20 kg puck has a speed of 0.5 m/s at an angle of θ = 53° to the positive x ...
*October 23, 2011 by Seth*

**Chemistry**

A 1.50 L buffer solution is 0.250 mol L-1 in HF and 0.250 mol L-1 in NaF. Calculate the pH of the solution after the addition of 0.0500 moles of solid NaOH. Assume no volume change upon the addition of the base. The Ka for HF is 3.5 × 10-4. Thanks in advance!
*June 21, 2015 by B*

**physics**

In the problem, please assume the free-fall acceleration g = 9.80 m/s2 unless a more precise value is given in the problem statement. Ignore air resistance. A stone is thrown vertically downward from the roof of a building. It passes a window 15.0 m below the roof with a speed...
*September 4, 2012 by kevin*

**General Physics**

A 4 kg block slides along a frictionless horizontal with a speed of 5.1 m/s. After sliding a distance of 7 m, the block makes a smooth transition to a frictionless ramp inclined at an angle of 13 degrees to the horizontal. The acceleration of gravity is 9.81 m/s2. How far up ...
*July 26, 2013 by Charles*

**physics**

A ball thrown straight upward returns to its original level in 2.50s. A second ball is thrown at an angle of 36.degrees above the horizontal. What is the initial speed of the second ball if it also returns to its original level in 2.50
*September 17, 2011 by elisa*

**physics**

a ball is thrown up and reaches a maximum height of 5 m. a) what is the initial velocity of the ball? b) how long does it take for the ball to reach its maximum height? c) what is the final velocity of the ball? if i returns to where it was thrown from?
*November 29, 2012 by Isis*

**Physics**

Suppose you’re eating in yet another restaurant where the dishes are shared at the table and all placed uniformly on a rotating disk-like surface. Model this surface as a thin disk of radius 30 cm. Someone else has spun the surface, such that it is initially at an angular ...
*April 22, 2016 by Santhiya *

**Physics**

A block of mass m1 = 6.25 kg on a frictionless plane inclined at angle θ = 30.7° is connected by a cord over a massless, frictionless pulley to a second block of mass m2 = 2.36 kg hanging vertically (Fig. 5-52). (a) What is the acceleration of the hanging block (choose ...
*October 16, 2011 by Ty*

**Physics **

A 0.2 kg baseball located at the top of a building which is 100 m above the ground is thrown with an initial velocity 30 m/s at an angle of 30o above the horizontal. (a) Determine the total energy which the ball will have just after the instant that the ball is thrown. (b) ...
*June 24, 2012 by Aria*

**Physics**

A mass of 2.2kg is placed on a stiff vertical spring which has a spring constant of 950n/m. The object is then pressed against the spring until it has been compressed a distance of 77cm. The mass is then released and is allowed to be thrown up into the air. How high in the ...
*February 25, 2012 by Rob*

**Calculus**

A mass on a spring vibrates horizontally on a smooth level surface (see the figure). Its equation of motion is x(t) = 8 sin t, where t is in seconds and x is in centimeters. The first part of the question is to find the velocity and acceleration equations, which I got to be: v...
*October 6, 2015 by kelly*

**american government**

In a dictatorship supreme authority rests solely with the people
*September 22, 2008 by cher taregan*

**Advanced Physic**

An 8.5 m extension ladder of mass 24 kg is propped up against a wall, touching at a point 8.0 m above the level ground. A man of mass 75 kg climbs 2.0 m up the ladder to repair a window. The ladder rests against a frictionless wall, but the ground has friction. Determine the ...
*May 14, 2014 by Anonymous*

**physics**

A 27-kg boy stands 4 m from the center of a frictionless playground merry-go-round, which has a moment of inertia of 238 kg m2. The boy begins to run in a circular path with a speed of 0.6 m/s relative to the ground. (a) Calculate the angular velocity of the merry-go-round. (b...
*March 26, 2011 by Nick*

**physics**

A 27-kg boy stands 4 m from the center of a frictionless playground merry-go-round, which has a moment of inertia of 238 kg m2. The boy begins to run in a circular path with a speed of 0.6 m/s relative to the ground. (a) Calculate the angular velocity of the merry-go-round. (...
*March 26, 2011 by Really stuck in this problem !!*

**Physics**

Two stones are thrown simultaneously, one straight upward from the base of a cliff and the other straight downward from the top of the cliff. The height of the cliff is 6.80 m. The stones are thrown with the same speed of 9.05 m/s. Find the location (above the base of the ...
*October 1, 2012 by Jackie Li*

**Chemistry**

A sample of krypton gas occupies 95.0 mL at 0.500 atm. If the temperature remained constant, what volume would the krypton occupy at (a) 5.00 atm, (b) 0.0500 atm, (c) 555 torr, (d) 5.00 torr, and (e) 5.5 3 1022 torr?
*April 28, 2015 by Alicia*

**Calculus**

Suppose that the region between the x-axis and the curve y=e^-x for x>=0 has been revolved around the x-axis. Find the surface area of the solid. I got 3*pi The book shows an answer of pi * [sqrt(2) + ln(1 + sqrt(2))] Where do I go wrong? For the sides of the surface, I ...
*January 13, 2008 by mathstudent*

**Physics**

A 23-kg boy stands 3 m from the center of a frictionless playground merry-go-round, which has a moment of inertia of 180 kg m2. The boy begins to run in a circular path with a speed of 0.6 m/s relative to the ground. (a) Calculate the angular velocity of the merry-go-round in ...
*June 18, 2012 by Maria*

**Math ASAP**

Height: 10 inches Base Perimeter: 40 inches Lateral Surface Area: 400 square inches (^^^this is the total surface area of the sides) What is the Surface Area of the triangular prism? (the picture of the shape looks like a pentagon but the rectangle is much longer)
*August 26, 2013 by Omar*

**Calc**

"Consider the surface given by 4x^2-y^2+5z^2-10z=55. a) Find all points on the surface at which the tangent plane is parallel to the plane 8x+y+15z=1. b) Pick one of these points and give the equation of the tangent plane to the surface at that point." Could someone help me ...
*March 1, 2011 by Anonymous*

**physics**

acceleration due to gravity questions when an object is dropped from a height of 10m above the surface of the planet z, it takes 1.2 seconds for the object to reach the surface. what is the acceleration of a falling object near the surface of the planet?
*February 25, 2010 by jake*

**Physics**

A ball thrown straight upward returns to its original level in 2.30 . A second ball is thrown at an angle of 38.0 degrees above the horizontal. What is the initial speed of the second ball if it also returns to its original level in 2.30 ?
*September 27, 2009 by Julia*

**uni physics **

A balloon of radius 30.0 cm is sprayed with a metallic coating so that the surface is conducting. A charge of 8.85×10−8 C is placed on the surface. What is the potential on the balloon's surface? 2.65×10^3 V Suppose that the some air is let out of the balloon, so that ...
*September 25, 2013 by Aman*

**physics - electric fields**

A 2.00 square meter flat surface is placed in a uniform electric field of magnitude 6.00 N/C. If the surface is oriented so that the field lines are all parallel to the surface, find the magnitude of the electric flux through this area
*September 8, 2013 by Lakitha*

**Physics**

Three blocks on a frictionless horizontal surface are in contact with each other, as shown below. A force F is applied to block A (mass mA). (a) Draw a free-body diagram for each block. Determine (b) the acceleration of the system (in terms of mA, mB, mC), (c) the net force on...
*October 22, 2010 by Anonymous*

**Physics**

Two objects are connected by a light string that passes over a frictionless pulley as in the fi gure. One object lies on a frictionless, smooth incline. In the figure, m1 = 8.48 kg, m2 = 4.84 kg, and theta = 40.2 degrees . When we let go of the mass m1, it accelerates ...
*January 27, 2013 by Lindsey*

**Physics**

The electric flux through the surface shown in Figure Ex27.10 is 15.0 Nm2/C, and the electric field makes an angle α = 70° with the surface. What is the electric field strength? The surface is a 10cm by 10cm square.
*September 13, 2010 by David D.*

**Physics**

A hockey puck of mass 0.16 kg, sliding on a nearly frictionless surface of ice with a velocity of 2.0 m/s (E), strikes a second puck at rest with a mass of 0.17 kg. the first puck has a velocity of 1.5 (N 31 E) after the collision. Determine the velocity of the second puck ...
*November 18, 2013 by Priyank*

**physics**

Suppose the stone is thrown at an angle of 30.0 degrees below the horizontal. If it strikes the ground 57.0 m away, find (a) the time of flight, (b) the initial speed, and (c) the speed and the angle of the velocity vector with respect to the horizontal at impact. (Hint: For ...
*October 14, 2015 by Adam*

**physics**

A 1.82 kg box moves back and forth on a horizontal frictionless surface between two different springs, as shown. The box is initially pressed against the stronger spring (k1 = 37.0 N/cm), compressing it 3.10 cm, and then is released from rest. By how much will the box compress...
*October 27, 2007 by Megan*

**Chemistry**

Sodium sulfate is slowly added to a solution containing 0.0500 M Ca^2+ (aq) and 0.0390 M Ag^+ (aq). What will be the concentration of Ca^2+ (aq) when Ag2SO4(s) begins to precipitate? What percentage of the Ca^2+ (aq) can be separated from the Ag^+ (aq) by selective ...
*March 17, 2013 by Anon*

**physics**

A block of mass m1 = 3.56 kg on a frictionless plane inclined at angle θ = 34.1° is connected by a cord over a massless, frictionless pulley to a second block of mass m2 = 2.72 kg hanging vertically (see the figure). (a) What is the acceleration of the hanging block (...
*March 17, 2016 by krals*

**Calculus**

a rectangular box of given volume is to be "a" times long as it is wide. find the dimension for which it has the least total surface area ? L= aw Total surface area= 2LW + 2Lh + 2Wh = 2aw^2 + 2awh + 2wh But volume= lwh= 2aw^2 h or h= V/2aw^2 Total Surface area= = 2aw^2 + 2awV/...
*December 10, 2006 by Hero*

**Physics**

A package is thrown down a curved ramp as shown in the figure. The package moves from A to B through a quarter-circle with radius R=3.00m. The mass of the package is 25.0kg. The package starts from rest at point A and there is no friction. A) Find the speed of the package at ...
*April 9, 2013 by Anonymous*

**physics**

Two toboggans are pulled across the ice with a force of 1.2 x 102 N. The rope of the toboggan makes an angle of 55o with the horizontal. The first toboggan has a mass of 25 kg, and the second toboggan has a mass of 16 kg. Assume that the ice surface is smooth enough to be ...
*April 25, 2012 by myra*

**algebra**

A ball is thrown upward with an initial velocity of 14 meters per second from a cliff that is high. The height of the ball is given by the quadratic equation H = 49t^2 + 14t +60 where h is in meters and t is the time in seconds since the ball was thrown. Find the time that the...
*March 4, 2013 by Sherrydoug2*

**physics**

A box containing food supplies for a refugee camp was dropped from a helicopter flying horizontally at a constant elevation of 414.1 m. If the box hit the ground at a distance of 95.3 m horizontally from the point of its release, ... a) what was the speed of the helicopter? b...
*October 16, 2015 by sandy*

**physics**

Consider an ideal spring that has an unstretched length l0 = 3.9 m. Assume the spring has a constant k = 20 N/m. Suppose the spring is attached to a mass m = 6 kg that lies on a horizontal frictionless surface. The spring-mass system is compressed a distance of x0 = 1.7 m from...
*October 11, 2013 by PLS HELP*

**Kinetic energy**

steel ball of mass 0.310 kg is fastened to a cord that is 86.0 cm long and fixed at the far end. The ball is then released when the cord is horizontal, as shown in the figure. At the bottom of its path, the ball strikes a 3.10 kg steel block initially at rest on a ...
*April 26, 2015 by Anonymous*

**physics**

Two towers(the towers are the same) are built next to each other. the distance between them is d and there height is 10,000d. a ball is thrown horizontally from one tower to the other with spped v=sqrt(gd/2). assuming the ball collied elasticlly with the wall, therfore his ...
*January 27, 2015 by larry*

**Physics - Mechanics**

A small block of mass 1.2 kg is launched by a compressed spring with force constant k=600 N/m. The initial compression of the spring is 0.15 m. The block slides along a horizontal frictionless surface and then up an inclined plane that makes an angle θ=40˚ with the ...
*March 13, 2015 by Anonymous*

**Physics - Mechanics**

A small block of mass 1.2 kg is launched by a compressed spring with force constant k=600 N/m. The initial compression of the spring is 0.15 m. The block slides along a horizontal frictionless surface and then up an inclined plane that makes an angle θ=40˚ with the ...
*March 14, 2015 by Anonymous*

**PHYSICS**

During heavy rain, a section of a mountainside measuring 5.4 km horizontally (perpendicular to the slope) 0.80 km up along the slope, and 2.1 m deep slips into a valley in a mud slide. Assume that the mud ends up uniformly distributed over a surface area of the valley ...
*February 1, 2013 by SARA *

**Algebra 2**

if an object is thrown vertically upward with an initial velocity of v from an original position of s, the height h at any time t is given by: h=-16t^2+vt+s (where h and s are in ft t is in seconds and v is in ft/sec) If a rock is thrown upward from a height of 100ft, with an ...
*April 23, 2014 by Bri*

**math (graphing)**

if f(x)= x+2, find the equation of the function F obtained by stretching the function f vertically by a factor of 2 and compressing the function horizontally by a factor of 2, followed by a translation of 1/2 horizontally and -3 vertically. the equation is: -x^2 - 6x - 7 what ...
*February 7, 2009 by ishi*

**algebra**

When a ball is thrown in the air, the height h of a ball in feet t seconds after the ball is thrown in the air, is given by the equation height = 25t–16t² Use the quadratic equation to determine how many seconds goes by before the ball hits the ground?
*May 7, 2012 by Coach*

**algebra**

When a ball is thrown in the air, the height h of a ball in feet t seconds after the ball is thrown in the air, is given by the equation height = 25t–16t² Use the quadratic equation to determine how many seconds goes by before the ball hits the ground?
*May 7, 2012 by Coach*

**math HELP**

When a ball is thrown in the air, the height h of a ball in feet t seconds after the ball is thrown in the air, is given by the equation height = 25t–16t² Use the quadratic equation to determine how many seconds goes by before the ball hits the ground?
*May 8, 2012 by Coach*

**physics help please**

The two blocks are connected by a light string that passes over a frictionless pulley with a negligible mass. The 3 kg block lies on a rough horizontal surface with a constant coefficient of kinetic friction 0:3. The hanging block has a mass of 8 kg. The system starts from ...
*March 1, 2007 by kitt*

**Pre Algebra**

I am doing an ice cream cone project for math on cones and had to figure out the surface area for them, but there is a question that is "how to the surface and lateral area of each relate?" my teacher said you will see a pattern but i dont. i.e. sa= 13,293.5 and la= 10,831.7 ...
*May 10, 2011 by Carrie*

**chemistry**

calcium hydroxide is titrated with nitric acid.What volume of 0.0200 M calcium hydroxide is required to neutralize 35.00 ml of 0.0500 M nitric acid?
*November 24, 2010 by vanessa*

**Physics**

Ok I got a question I asked before except there are other parts that I didn't ask so here we go Three blocks on a frictionless horizontal surface are in contact with each other A force F is applied to block 1 (mass m1). Draw a free-body diagram for each block ok I did this the...
*July 12, 2009 by Physics*

**physics**

To push a 25.0kg crate up a frictionless surface incline angled at 25 degrees to the horizontal, a worker exerts a force of magnitude 209N parallel to the incline. As the crate slides 1.50m, how much work is done on they crate by (a) the worker's applied force, (b) the ...
*November 2, 2010 by Lyss*

**physics**

A block of mass m1=3.70kg on a frictionless plane inclined at angle 30 deg is connected by a cord over a massless, frictionless pulley to a second block mass m2= 2.30kg. What is... a) The magnitude of the acceleration of each block? b) The direction of the acceleration of the ...
*January 12, 2016 by Maryam*

**college physics**

A 0.384 kg puck, initially at rest on a horizon- tal, frictionless surface, is struck by a 0.189 kg puck moving initially along the x axis with a speed of 2.7 m/s. After the collision, the 0.189 kg puck has a speed of 1.7 m/s at an angle of 28 to the positive x axis. ...
*October 22, 2011 by Tom*

**Physics**

Part 1: Two balls (Ball 1 and Ball 2) are released from the top of a tower. Ball 2 is thrown 3.14 seconds after Ball 1 is dropped. Ball 2 is thrown downward with a velocity of 3.49 m/s. Determine how far apart Ball 1 and Ball 2 are after 5.02 seconds from when Ball 1 was ...
*September 12, 2012 by Ashley*

**Physics**

Part 1: Two balls (Ball 1 and Ball 2) are released from the top of a tower. Ball 2 is thrown 3.14 seconds after Ball 1 is dropped. Ball 2 is thrown downward with a velocity of 3.49 m/s. Determine how far apart Ball 1 and Ball 2 are after 5.02 seconds from when Ball 1 was ...
*September 12, 2012 by Ashley*

**math**

if f(x)= x+2, find the equation of the function F obtained by stretching the function f vertically by a factor of 2 and compressing the function horizontally by a factor of 2, followed by a translation of 1/2 horizontally and -3 vertically. the equation is: -x^2 - 6x - 7 what ...
*February 8, 2009 by isha*

**Physics - Projectile Motion**

A ball rolls horizontally off the edge of a tabletop that is 1.60 m high. It strikes the floor at a point 1.58 m horizontally away from the table edge. (Neglect air resistance.) (a) How long was the ball in the air? ___ s (b) What was its speed at the instant it left the table...
*February 1, 2007 by TechnoBoi11*

**Physics**

A ball is thrown upwards, from a building. It's height(h), in meters above the ground seconds(t) after being thrown is given by h(t)=-5t^2+15t+50 a) How tall is the building? (explain your answer) b) How long does it take the ball to reach the ground? c) For how long is the ...
*September 3, 2014 by Anonymos*

**Physics**

A 4kg box is attached to a 2.4m rope rotating on platform. Max tension can withstand without breaking is 140N. 1.) Find Max. speed w/ which the box can rotate if the surface of platform is frictionless. 2.) Find Max speed w/ which box can rotate if Coeff. of friction between ...
*March 17, 2016 by Kelly*

**physics**

A mass-spring system oscillates on a horizontal frictionless surface with an amplitude of 3.35 cm. If the spring constant is 222 N/m and the mass is 0.580 kg, determine the mechanical energy of the system. Determine the maximum speed of the mass. Determine the maximum ...
*April 7, 2016 by Anonymous*

**English expression**

Let's learn the conjugation of the verb throw. What is the past tense of throw? It is threw. Then what is the past participle of the verb throw? It's thrown. OK. Good job. Repeat after me. Throw. Threw. Thrown. Good. Well done. ------------------------- Are the sentences ...
*March 28, 2008 by John*

**physics**

Each of 108 identical blocks sitting on a frictionless surface is connected to the next block by a massless string. The first block is pulled with a force of 108N. Part A. What is the tension in the string connecting block 108 to block 107? Part B. What is the tension in the ...
*October 9, 2011 by Josh*

**physics**

Two stones are thrown simultaneously, one straight upward from the base of a cliff and the other straight downward from the top of the cliff. The height of the cliff is 6.82 m. The stones are thrown with the same speed of 8.88 m/s. Find the location (above the base of the ...
*January 24, 2015 by Syd*

**Bn**

(a) A luggage carousel at an airport has the form of a section of a large cone, steadily rotating about its vertical axis. Its metallic surface slopes downward toward the outside, making an angle of 29.0° with the horizontal. A piece of luggage having mass 30.0 kg is placed on...
*February 29, 2016 by Mohammed *

**Physics**

Eris, the largest dwarf planet known in the Solar System, has a radius R = 1200 km and an acceleration due to gravity on its surface of magnitude g = 0.77 m/s2. (a) Use these numbers to calculate the escape speed from the surface of Eris. (b) If an object is fired directly ...
*June 29, 2012 by James*

**science**

a 600 g pool ball moving at 2.0m/s hits a second pool of the same mass at rest. the first ball moves off at 1.5m/s at an angle of 30 degrees from the original direction. assume the surface of the pool table to b frictionless find the angle at which the second ball moves off ...
*April 7, 2016 by hope*

**A plane flies horizontally at an altitude of 5 km **

A plane flies horizontally at an altitude of 5 km and passes directly over a tracking telescope on the ground. When the angle of elevation is π/3, this angle is decreasing at a rate of π/4 rad/min. How fast is the plane traveling at that time? (Round your answer to ...
*March 14, 2011 by yolana*

**physic**

9. A 2.00-kg object is attached to a spring and placed on a frictionless, horizontal surface. A horizontal force of 20.0 N is required to hold the object at rest when it is pulled 0.200 m from its equilibrium position (the origin of the x axis). The object is now released from...
*June 29, 2013 by Ika Diana*

**Physics**

A knife thrower throws a knife toward a 300-g target that is sliding in her direction at a speed of 2.30 m/s on a horizontal frictionless surface. She throws a 22.5-g knife at the target with a speed of 39.5 m/s. The target is stopped by the impact and the knife passes through...
*March 4, 2014 by Timothy*

**Physics**

The amount of heat per second conducted from the blood capillaries beneath the skin to the surface is 250 J/s. The energy is transferred a distance of 1.7 x 10-3 m through a body whose surface area is 1.8 m2. Assuming that the thermal conductivity is that of body fat, ...
*April 30, 2013 by Tim*

**physics**

A block of mass m = 3.6 kg, moving on a frictionless surface with a speed vi=9.3m/s makes a perfectly elastic collision with a block of mass M at rest. After the collision, the 3.6 kg block recoils with a speed of vf=2.7m/s. In Figure 8.2, the speed of the block of mass M ...
*November 16, 2012 by terry*

**physics**

at 25.0m below the surface of the sea (density=1.025kg/m^3), where the temperature is 5.00C, a diver exhales an air bubble having a volume of 1.00cm^3. If the surface temperature of the sea is 20.0C, what is the volume of the bubble just before it breaks the surface?
*December 3, 2009 by james*

**lens surface**

- a spherical generator is used to produce a -15.00D surface on glass of refractive index 1.80. The diameter of the cutting tool is 80mm and the radius of the cutting surface is 4 mm. What is the angle between the axis of the tool and the axis of the lens?
*October 22, 2012 by Anonymous*

**Physics**

At 30.0 m below the surface of the sea (density = 1025 kg/m3), where the temperature is 5.00°C, a diver exhales an air bubble having a volume of 0.80 cm3. If the surface temperature of the sea is 20.0°C, what is the volume of the bubble just before it breaks the surface?
*January 19, 2010 by jenn*

**physics**

a cube of side L is made of a substance that is 1/4 as dense as water. WHen placed in a calm water bath the cube will a) float with 1/2 L abovethe surface b)sink to the bottom, c) float with 1/4 L above the surface d) float with 1/4 L below the surface e) float with 3ã1/4
*January 8, 2012 by anna*

**physics**

A baseball is thrown with an initial velocity of magnitude v at an angle of 27.2 with respect to the horizontal (x) direction. At the same time, a second ball is thrown with the same initial speed at a different angle with respect to x. If the two balls land at the same spot, ...
*January 30, 2010 by Sal*

**Physics **

Two stones are thrown simultaneously, one straight upward from the base of a cliff and the other straight downward from the top of the cliff. The height of the cliff is 5.53 m. The stones are thrown with the same speed of 8.62 m/s. Find the location (above the base of the ...
*September 13, 2014 by Steven*

**11 Physics**

my teacher gave me this question for review and i don't know how to do it!! HELP!!! A ball is thrown upwards, from a building. It's height(h), in meters above the ground seconds(t) after being thrown is given by h(t)=-5t^2+15t+50 a) How tall is the building? (explain your ...
*September 3, 2014 by Sam*

**college physics**

Two forces, of magnitudes F_1 = 80.0 N and F_2 = 25.0 N, act in opposite directions on a block, which sits atop a frictionless surface. Initially, the center of the block is at position x_i = -4.00 cm. At some later time, the block has moved to the right, and its center is at ...
*February 25, 2010 by coco*

**Physic**

Block A of mass 2.2 kg is on block B of mass 5.2 kg as shown in the above figure. The lower block is on a frictionless surface while the coefficient of static friction is 0.3 between the two blocks. a) If they are moving at constant velocity, what is the frictional force ...
*October 25, 2015 by Anonimea*

**Physics**

A 0.18 kg point mass moving on a frictionless horizontal surface is attached to a rubber band whose other end is fixed at point P. The rubber band exerts a force F = bx toward P, where x is the length of the rubber band and b is an unknown constant. The mass moves along the ...
*November 4, 2010 by Jessica*

**college physics**

Two blocks of masses m1 = 4.00 kg and m2 = 3.00 kg are placed in contact with each other on a frictionless horizontal surface. A constant force F = 9.00 N is applied to the block of mass m1. a) Determine the magnitude of the acceleration of the two-block system. b) Determine ...
*February 11, 2012 by lacrosse*

**Physics**

The gravitational potential difference between the surface of a planet and a point P, 10 m above the surface, is 8.0 J kg-1. Assuming a uniform field, what is the value of the gravitational field strength in the region between the planet’s surface and P?
*January 19, 2011 by Christine*

**physics**

A 0.45 kg soccer ball approaches a player horizontally with a velocity of magnitude equal to 35 m/s. The player heads the ball straight back out horizontally, and the magnitude of the ball’s velocity after the collision is 40 m/s. The contact time between their head and the ...
*July 12, 2012 by Jessica*