Saturday
March 28, 2015

# Homework Help: Science: Physics

physics
If the speed of the cart at the first photogate is 2.3 m/s, and the speed of the cart at the first photogate is 1.8 m/s, what is the percentage change in the speed of the cart (LEAVE OUT the % symbol)?
Thursday, March 20, 2014 at 9:25am

physics
If the average time from one on state to the next one on the first photogate is 0.005 seconds, what is the speed of the cart at this point (LEAVE OUT the units of m/s)?
Thursday, March 20, 2014 at 9:19am

Physics
If you have three waves corresponding to to the lowest three frequencies of vibrations of a 30 cm air column, what is the wavelength of the standing wave in each case? What frequency is heard in each pipe? The only information I have is that the speed of sound in air is 331 m/s
Thursday, March 20, 2014 at 6:02am

Physics
A Plane flies north at 215 km/h. A wind from the east blows at 69km/h. What is the plane's new velocity with respect to the ground in standard position
Wednesday, March 19, 2014 at 11:02pm

physics
A force in the +x-direction with magnitude F(x)=18.0N−(0.530N/m)x is applied to a 7.60kg box that is sitting on the horizontal, frictionless surface of a frozen lake. F(x) is the only horizontal force on the box. If the box is initially at rest at x=0, what is its speed ...
Wednesday, March 19, 2014 at 9:35pm

Physics
Calculate the force of friction that keeps a 80-kg person sitting on the edge of a horizontal rotating platform when the person sits 2.4m from the center of the platform and has a tangential speed of 3.2m/s . Express your answer to two significant figures and include the ...
Wednesday, March 19, 2014 at 8:51pm

Physics.
Calculate the tension in a horizontal string that whirls a 1.9-kg toy in a circle of radius 2.3m when it moves at 2.8m/s on an icy surface. Express your answer to two significant figures and include the appropriate units
Wednesday, March 19, 2014 at 8:50pm

Physics!
Consider someone in a rotating space habitat. The outward force felt by the person A.has no reaction counterpart B.is an interaction with Earth C.is a form of gravity D.is real in the traditional sense
Wednesday, March 19, 2014 at 8:07pm

physics
what is the magnetic flux of a magnetic field of 3.5 x 10 T lassing a given circular surface with radius 30 cm
Wednesday, March 19, 2014 at 8:01pm

Physics
I once was given a metal whiskey flask for being in my cousin’s wedding. When it got dented, I put in 1 gram of H2O (initially 21°C, just like the air filling the rest of the flask) and heated it up to boil the water. It popped the dent out. Assume the flask had a ...
Wednesday, March 19, 2014 at 8:00pm

Physics
A 5.00-g bullet is fired into a 500-g block of wood suspended as a ballistic pendulum. the combined mass swings up to a height of 8.00 cm. What was the magnitude of the momentum of the combined mass immediately after the collision? Answer a. 0.394 kg·m/s b. 0.632 kg&...
Wednesday, March 19, 2014 at 5:48pm

Physics
A 5.00-g bullet is fired into a 500-g block of wood suspended as a ballistic pendulum. the combined mass swings up to a height of 8.00 cm. What was the magnitude of the momentum of the combined mass immediately after the collision?
Wednesday, March 19, 2014 at 5:47pm

Physics
A 11 kg box slides 4.2 m down a frictionless ramp and then collides with a spring whose spring constant is 250 N/m. What is the maximum compression of the spring? I got 1.35 m but it is incorrect. Any help would be great!
Wednesday, March 19, 2014 at 3:51pm

Algebra Based Physics
A 2.50-kg steel ball strikes a massive wall at 10.0 m/s at an angle of θ = 60.0° with the plane of the wall. It bounces off the wall with the same speed and angle (see the figure below). If the ball is in contact with the wall for 0.224 s, what is the average force ...
Wednesday, March 19, 2014 at 2:28pm

Physics
Bats chirp at a high frequency which humans cannot hear. They use the echoes to detect small objects, such as insects, as small as one wavelength. If a bat were to emit a chirp at a frequency of 60.0 kHz and the speed of sound waves in the air are 340 m.s, what is the size in ...
Wednesday, March 19, 2014 at 2:15pm

physics question for damon (a clarification)
Hi Damon! You helped me out in this question yesterday (jiskha. com /display.cgi?id = 1395185605) and I was wondering why you added gravity when calculating the friction. Thanks for your help!
Wednesday, March 19, 2014 at 1:55pm

physics
A cylinder floats with its volume 3 cubic metre inside water. What is its total volume if its density 100 kg per cubic metre? Density of water is 1000 kg per cubic metre
Wednesday, March 19, 2014 at 11:17am

Physics
Prove that tanø is equal to U(k) when the block slides down the incline with a constant speed. (Use symbols, not numbers.)
Wednesday, March 19, 2014 at 9:38am

physics
Two cars start off a race with initial velocities u0 and v0, and travel in a straight line with uniform acceleration á and â. If the race ends in a dead beat, prove that the length s of the race is: s=(2(u_0-v_0)(u_0 â-v_0 á))/(â-á)^2
Wednesday, March 19, 2014 at 9:37am

physics
A pitcher throws a 0.198-kg baseball, and it approaches the bat at a speed of 57.5 m/s. The bat does 85.1 J of work on the ball in hitting it. Ignoring air resistance, determine the speed of the ball after the ball leaves the bat and is 32.7 m above the point of impact.
Wednesday, March 19, 2014 at 6:49am

physics
The drawing shows a skateboarder moving at 6.93 m/s along a horizontal section of a track that is slanted upward by 45.6 ° above the horizontal at its end, which is 0.654 m above the ground. When she leaves the track, she follows the characteristic path of projectile ...
Wednesday, March 19, 2014 at 2:47am

physics
A sign is hanging from the ceiling on two threads of equal length, which make an angle $\theta$ of 108.5 "degrees" with each other. What is the tension (in N) in each thread, assuming that the force of gravity acting on the sign is 46.5 N?
Tuesday, March 18, 2014 at 10:46pm

Physics
(Need Help Only For Last Question! I figured out the first two.) A car of mass m = 1130 kg is traveling down a θ = 11 degree incline. When the car's speed is v0 = 11 m/s, a mechanical failure causes all four of its brakes to lock. The coefficient of kinetic friction ...
Tuesday, March 18, 2014 at 10:32pm

Physics
A 60 kg girl on a swing is pulled 1.5 meters back and then released. The girl oscillates at pi/3 radians per second. How far from equilibrium will the girl be in 4 seconds into the motion? How fast will she be moving at this location?
Tuesday, March 18, 2014 at 10:22pm

physics
The angle of incidence and the angle of refraction for light going from air into a material with a higher index of refraction are 69.9° and 39.6°, respectively. What is the index of refraction of this material?
Tuesday, March 18, 2014 at 10:17pm

Physics
During a free kick at a soccer playoff game a 0.5 kg ball at the peak of the kick 16.6 m above the field had a kinetic energy of 35.4 J. How fast was the ball booted by the player on the field?
Tuesday, March 18, 2014 at 9:16pm

Honors Physics
0.5 kg ball at the peak of the kick 16.6 m above the field had a kinetic energy of 35.4 J. How fast was the ball booted by the player on the field?
Tuesday, March 18, 2014 at 9:15pm

Physics
If the work required to stretch a spring 4 feet beyond its natural length is 17 foot-pounds, how much work is needed to stretch it 14 inches beyond its natural length? Your answer must include the correct units. (You may enter lbf or lb*ft for ft-lb.)
Tuesday, March 18, 2014 at 9:14pm

simple physics
You push downward on a box at an angle 25° below the horizontal with a force of 750 N. If the box is on a flat horizontal surface for which the coefficient of static friction with the box is 0.73, what is the mass of the heaviest box you will be able to move?
Tuesday, March 18, 2014 at 7:33pm

PHYSICS
A 5.00-kg box slides 7.00 m across the floor before coming to rest. What is the coefficient of kinetic friction between the floor and the box if the box had an initial speed of 3.00 m/s?
Tuesday, March 18, 2014 at 7:09pm

Physics
A force of 9.4N pulls horizontally on a 1.2-kg block that slides on a rough, horizontal surface. This block is connected by a horizontal string to a second block of mass m2 = 2.00kg on the same surface. The coefficient of kinetic friction is μk = 0.25 for both blocks. ...
Tuesday, March 18, 2014 at 6:21pm

physics
A 5.0-nC charge is at (0, 0) and a -2.0-nC charge is at (3.0 m, 0). If the potential is taken to be zero at infinity, what is the electric potential energy of a 1.0-nC charge at point (0, 4.0 m)? Answer 1.5 × 10-8 J 3.6 × 10-9 J 1.1 × 10-8 J 7.7 × 10-9 J
Tuesday, March 18, 2014 at 1:39pm

physics
What is the minimal resistance of a 100 W light bulb designed to be used in a 120 V circuit? Answer 12.0 Ω 144 Ω 1.2 Ω 0.83 Ω
Tuesday, March 18, 2014 at 1:13pm

physics
A 3.0-kg object moving 8.0 m/s in the positive x direction has a one-dimensional elastic collision with an object (mass = M) initially at rest. After the collision the object of unknown mass has a velocity of 6.0 m/s in the positive x direction. What is M?
Tuesday, March 18, 2014 at 11:01am

Physics
If you try to lift a 2 x 10 plank by applying 25 N force but plank does not move did you do any work?
Tuesday, March 18, 2014 at 10:42am

Physics
How would i solve this? (30)(Cm)Δ+(335.5)(4.18)Δ(21)=0​
Tuesday, March 18, 2014 at 8:54am

physics
A bullet A of mass 2kg travelling at 200m/s emblezes itself in a wooden block of mass 9kg moving in the opposite direction. At 20m/s. Calculate the velocity of the block when the bullet comes to rest inside the block. And what principle is used in the direction
Tuesday, March 18, 2014 at 3:59am

physics
A skateboard with mass M rolls down a ramp, starting from rest. It takes time T to roll a distance L along the ramp. In terms of M, T, and L, what is the skateboard’s acceleration down the ramp?
Tuesday, March 18, 2014 at 1:00am

physics
The drawing shows a skateboarder moving at 7.59 m/s along a horizontal section of a track that is slanted upward by 55.0 ° above the horizontal at its end, which is 0.741 m above the ground. When she leaves the track, she follows the characteristic path of projectile ...
Monday, March 17, 2014 at 10:50pm

Physics
A truck with 0.100 m radius tires travels at 24.0 m/s. At how many radians per second are the tires rotating? What is this in rpm?
Monday, March 17, 2014 at 10:10pm

Physics
An automobile with 0.310 m radius tires travels 85,000 km before wearing them out. How many revolutions do the tires make, neglecting any backing up and any change in radius due to wear?
Monday, March 17, 2014 at 10:10pm

Physics
In lacrosse, a ball is thrown from a net on the end of a stick by rotating the stick and forearm about the elbow. If the angular velocity of the ball about the elbow joint is 30.0 rad/s and the ball is 1.05 m from the elbow joint, what is the velocity of the ball?
Monday, March 17, 2014 at 10:10pm

physics
Complete the following nuclear reaction: ^16,v8 O + ^4, v2 He → ________ + ^19, v10 Ne 1p 1n 2H 3H
Monday, March 17, 2014 at 9:57pm

Physics
A basketball player is running at 5.00 m/s directly toward the basket when he jumps into the air to dunk the ball. He maintains his horizontal velocity. (a) What vertical velocity does he need to rise 0.750 meters above the floor? (b) How far from the basket (measured in the ...
Monday, March 17, 2014 at 9:18pm

Physics
An archer shoots an arrow at a 78.0 m distant target, the bull's-eye of which is at same height as the release height of the arrow. (a) At what angle must the arrow be released to hit the bull's-eye if its initial speed is 34.0 m/s? (Although neglected here, the ...
Monday, March 17, 2014 at 9:17pm

PHYSICS
You throw a 20-N rock vertically into the air from ground level. You observe that when it is a height 14.8m above the ground, it is traveling at a speed of 25.0m/s upward. A) Use the work-energy theorem to find its speed just as it left the ground. What is it? B) Use the work-...
Monday, March 17, 2014 at 8:41pm

language arts -
Need to confirm if the verbs in the sentences are physical or mental actions: 1. Other Americans in the Olympics challenged their opponents, too. --physics 2. Wilma dazzled the crowds in the track & field competition. --physical 3. Al Oerter, an American discus thrower, ...
Monday, March 17, 2014 at 8:25pm

Physics
A hammer of mass M is moving at speed v0 when it strikes a nail of negligible mass that is stuck in a wooden block. The hammer is observed to drive the nail a distance L deeper into the block. A) Find the magnitude F of the force that the wooden block exerts on the nail, ...
Monday, March 17, 2014 at 8:19pm

Physics
(30)(Cm)Δ+(335.5)(4.18)Δ(21)=0​ I need to find the specific heat of the masses, but i don't know how to, i'm currently doing a lab and these are the mass and temp. numbers that i plugged in...
Monday, March 17, 2014 at 8:17pm

Physics
You throw a 20-N rock vertically into the air from ground level. You observe that when it is a height 14.8m above the ground, it is traveling at a speed of 25.0m/s upward. A) Use the work-energy theorem to find its speed just as it left the ground. What is it? B) Use the work-...
Monday, March 17, 2014 at 8:03pm

Physics
A pump is required to lift a mass of 750kg of water per minute from a well of depth 13.2m and eject it with a speed of 17.4m/s. A) How much work is done per minute in lifting the water? B) How much in giving the water the kinetic energy it has when ejected? C) What must be the...
Monday, March 17, 2014 at 7:26pm

Physics
A factory worker pushes a 29.2kg crate a distance of 4.1m along a level floor at constant velocity by pushing downward at an angle of 28 degrees below the horizontal. The coefficient of kinetic friction between the crate and floor is 0.25. (a) What magnitude of force must the ...
Monday, March 17, 2014 at 7:04pm

help ms sue lang arts
For Questions 1–6, read the play excerpt below and answer the questions that follow. Jaws of the Water ACT TWO At rise we see DAD, TINA, and MARK rushing in and out of the living room. Each enters carrying important items—such as sleeping bags, rain gear, and ...
Monday, March 17, 2014 at 7:04pm

Physics
I need help with my lab, it's telling me to measure the mass of cup 1, but i don't understand how to measure it... I have a digital scale does that measure mass? or is there a certain equation to measure it?
Monday, March 17, 2014 at 6:15pm

physics
The magnitude of the magnetic field produced by a long straight current-carrying wire is: proportional to both the current in the wire and the distance from the wire proportional to the current in the wire and inversely proportional to the distance from the wire inversely ...
Monday, March 17, 2014 at 5:26pm

physics
A potter's wheel is rotating around a vertical axis through its center at a frequency of 1.8rev/s . The wheel can be considered a uniform disk of mass 4.7kg and diameter 0.34m . The potter then throws a 3.1kg chunk of clay, approximately shaped as a flat disk of radius ...
Monday, March 17, 2014 at 4:02pm

Physics
Suppose you pluck a string on a guitar and it produces the note A at a frequency of 440 Hz. Now, you press your finger down on the string against one of the frets, making this point the new end of the string. The newly shortened string has 4/5 the length of the full string. ...
Monday, March 17, 2014 at 3:56pm

Physics
Smoking causes blood vessels to constrict. If the average blood vessel radius of a smoker decreases 7.6% and the body increases blood pressure to maintain a constant flow. Calculate the needed percent increase in pressure.
Monday, March 17, 2014 at 3:19pm

Physics
An artery supplying heat muscle with blood is occluded to 13.9% of its original radius by a clot. By what percent is the blood flow through this artery reduced.
Monday, March 17, 2014 at 3:18pm

Physics
Neglecting the pressure drop due to resistance, calculate the blood pressure in mmHg in an artery in the brain 32 cm above the heart. The pressure at the heart is 120mmHg and the density of blood is 1.05g/cm3.
Monday, March 17, 2014 at 3:16pm

Physics
A full term fetus may have a mass of 3.3 kg . If the entire weight of the fetus rests momentarily on the mother's bladder, supported on an area of 78.8 cm2 calculate the pressure exerted in mmHg.
Monday, March 17, 2014 at 3:15pm

physics
What is the ratio of the speed of sound in air at 0°C to the speed at 100°C?
Monday, March 17, 2014 at 3:02pm

physics
A convex spherical mirror has a focal length of -20 cm. An object is placed 30 cm in front of the mirror on the mirror's axis. Where is the image located? Answer 12 cm in front of the mirror 60 cm behind the mirror 60 cm in front of the mirror none of the given answers
Monday, March 17, 2014 at 2:56pm

Physics
A high efficiency natural gas furnace is 92% efficient. How many joules of output energy will 750kJ of input fuel provide? Please help! Thank you.
Monday, March 17, 2014 at 1:57pm

Physics
At the point of fission, a nucleus of 235U that has 92 protons is divided into two smaller spheres, each of which has 46 protons and a radius of 5.11 ✕ 10-15 m. What is the magnitude of the repulsive force pushing these two spheres apart?
Monday, March 17, 2014 at 10:57am

Physics
A linear spring of stiffness k is designed to stop the 20-Mg railroad car traveling at 8 km/h within 400mm after impact. Find the smallest value of k that will produce the desired result.
Monday, March 17, 2014 at 8:45am

physics
the frequency of wave A is 250 hertz and the wavelength is 30 cm. the frequency of wave B is 260 hertz and the wavelength is 25 cm. which is a faster wave?
Monday, March 17, 2014 at 2:03am

A 540 g block is released from rest at height h0 above a vertical spring with spring constant k = 320 N/m and negligible mass. The block sticks to the spring and momentarily stops after compressing the spring 19.8 cm. How much work is done (a) by the block on the spring and (b...
Sunday, March 16, 2014 at 11:58pm

Physics
Three point charges of 8 C, 3 C, and -5 C, are locate at the top, bottom left, and bottom right corners respectively of an equilateral triangle of side 1Å. Find the magnitude and direction of the net force on the 3 C charge.
Sunday, March 16, 2014 at 11:08pm

physics
Light enters a container of liquid at an angle of 35° to the normal; the refracted beam makes an angle of 21° with the normal. Calculate the index of refraction of this liquid.
Sunday, March 16, 2014 at 8:40pm

Physics
A 540 g block is released from rest at height h0 above a vertical spring with spring constant k = 320 N/m and negligible mass. The block sticks to the spring and momentarily stops after compressing the spring 19.8 cm. How much work is done (a) by the block on the spring and (b...
Sunday, March 16, 2014 at 7:38pm

Physics
A 2.2 C charge is located on the x-axis at x = -1.5 m. A 5.4 C charge is located on the x-axis at x = 2.0m. A 3.5 C charge is at the origin. Find the net force acting on the 3.5 C charge.
Sunday, March 16, 2014 at 6:54pm

Physics
A 2.2 C charge is located on the x-axis at x = -1.5 m. A 5.4 C charge is located on the x-axis at x = 2.0m. A 3.5 C charge is at the origin. Find the net force acting on the 3.5 C charge.
Sunday, March 16, 2014 at 6:54pm

physics
A force of 15N acts in the forward direction on a carton of 3kg. Suppose a friction force of 6N opposes the carton motion. Find the following: 1) the net force 2) the acceleration of the carton
Sunday, March 16, 2014 at 6:20pm

Physics
A 2.2 uC charge is located on the x-axis at x = -1.5 m. A 5.4 uC charge is located on the x-axis at x = 2.0m. A 3.5 uC charge is at the origin. Find the net force acting on the 3.5 C charge.
Sunday, March 16, 2014 at 6:15pm

physics
calculate the heat given up when 0.1kg of steam at 100¡ã© condenses to h20 at 40¡ã©(s.l.h of vaporisation = 2.2¡Á10^6) (c=4200)
Sunday, March 16, 2014 at 5:13pm

PHYSICS
A 0.380 kg pendulum bob passes through the lowest part of its path at a speed of 2.03 m/s. What is the tension in the pendulum cable at this point if the pendulum is 83.1 cm long? When the pendulum reaches its highest point, what angle does the cable make with the vertical? ...
Sunday, March 16, 2014 at 4:06pm

physics
A 28000 kg railroad freight car collides with a stationary caboose car. They couple together, and 20 percent of the initial kinetic energy is dissipated as heat, sound, vibrations, and so on. What is the mass of the caboose?
Sunday, March 16, 2014 at 3:19pm

Physics
no matter how i work it out, i keep getting the wrong answers. please help!!! i only have two more submissions before it closes on me. A sample of blood is placed in a centrifuge of radius 14.0 cm. The mass of a red blood cell is 3.0 x 10^-16 kg, and the magnitude of the force...
Sunday, March 16, 2014 at 3:18pm

PHYSICS
Scientists are experimenting with a kind of gun that may eventually be used to fire payloads directly into orbit. In one test, this gun accelerates a 8.9-kg projectile from rest to a speed of 4.2 × 103 m/s. The net force accelerating the projectile is 1.4 × 105 N. ...
Sunday, March 16, 2014 at 12:38pm

Chemistry
The net reaction for fusion on a star like our Sun is: 4H(1,1) ==> He(4,2) + 2e(0,+1) Calculate the mass defect for this reaction. If one atom of He is formed this way, calculate the energy released. If one Kg of He is formed, calculate the energy released. The masses of ...
Sunday, March 16, 2014 at 12:07pm

Physics
A .75kg block is going at a velocity of 1.5m/s and moves on a frictionless surface. Then all of a sudden, the block hits a rough patch. The rough patch is .5m long and has a coefficient of friction of .25. Then it slides onto the frictionless surface again. The mass then ...
Sunday, March 16, 2014 at 11:34am

Physics
A man wishes to cross a river from A to B, a distance of 800m. He can row at 8km per hour, in what direction should he head the boat to travel directly from A to B? How long does it take him to reach B? Please show working. Thank You!
Sunday, March 16, 2014 at 10:06am

Physics
The acceleration of a particle moving only on a horizontal xy plane is given by a=5ti+6tj, where a is in meters per second-squared and t is in seconds. At t=0, the position vector r=(19.0m)i+(39.0m)j locates the particle, which then has the velocity vector v=(5.70m/s)i+(3.40m/...
Saturday, March 15, 2014 at 11:16pm

Physics
torque to move a block of m=200kg for 10m at an angle of 25 degree with a speed of 20m/s.
Saturday, March 15, 2014 at 9:20pm

Physics
A 49.5-kg skater is traveling due east at a speed of 2.88 m/s. A 72.5-kg skater is moving due south at a speed of 6.82 m/s. They collide and hold on to each other after the collision, managing to move off at an angle south of east, with a speed of vf. (a) Find the angle. (b) ...
Saturday, March 15, 2014 at 6:04pm

physics
A 12.0 g bullet is fired into a 13.9kg wooden block that is hanging straight down, suspended by a 2.00 m length of light line. The bullet has a muzzle velocity of 94.2 m/s. When the bullet hits the block, the bullet stays in the block. The block swings outward so that the line...
Saturday, March 15, 2014 at 6:01pm

Physics
The Achilles tendon is attached to the rear of the foot. Assume that a person has a mass of 53 kg and that D is twice as long as d. When a person elevates himself just barely off the floor on the "ball of one foot," estimate the tension in the Achilles tendon (...
Saturday, March 15, 2014 at 5:58pm

physics
(a) Suppose a hockey puck slides down a frictionless ramp with an acceleration of 5.60 m/s2. What angle does the ramp make with respect to the horizontal?
Saturday, March 15, 2014 at 5:14pm

Physics
Suppose the hand in holds a 20 kg mass . What force, FM, is required of the deltoid muscle? Assume the mass is 50 cm from the shoulder joint, the force of tension in the deltoid is directed 15° to the horizontal, and the mass of the arm alone is 3.8 kg.
Saturday, March 15, 2014 at 5:07pm

Physics
A block of mass 2.48 kg is kept at rest as it compresses a horizontal massless spring (k= 113 N/m) by 4.65 cm. As the block is released, it travels 0.462 m on a rough horizontal surface before stopping. The acceleration of gravity is 9.8 m/s^2. Calculate the coefficient of ...
Saturday, March 15, 2014 at 4:41pm

Physics
1. A 3 kg block collides with a massless spring of spring constant 90 N/m attached to a wall. The speed of the block was observed to be 1.5 m/s at the moment of collision. The acceleration of gravity is 9.8 m/s^2. How far does the spring compress if the surface on which the ...
Saturday, March 15, 2014 at 4:39pm

Physics
A racing car has a mass of 1530 kg. The acceleration of gravity is 9.8 m/s^2. What is its kinetic energy if it has a speed of 136 km/h? Answer in units of J.
Saturday, March 15, 2014 at 4:22pm

Physics
Shawn and his bike have a total mass of 58.5 kg. Shawn rides his bike 0.54 km in 17.2 min at a constant velocity. The acceleration of gravity is 9.8 m/s^2. What is Shawn’s kinetic energy? Answer in units of J.
Saturday, March 15, 2014 at 4:20pm

Physics
A team of dogs drags a 151 kg sled 0.863 km over a horizontal surface at a constant speed. The coefficient of friction between the sled and the snow is 0.223.The acceleration of gravity is 9.8 m/s^2. 1. Find the work done by the dogs. Answer in units of kJ. 2. Find the energy ...
Saturday, March 15, 2014 at 4:18pm

Physics
A cart loaded with bricks has a total mass of 22.3 kg and is pulled at constant speed by a rope. The rope is inclined at 27.3◦ degrees above the horizontal and the cart moves 9.3 m on a horizontal surface. The coefficient of kinetic friction between ground and cart is 0....
Saturday, March 15, 2014 at 4:15pm

Physics
A uniform ladder of mass m = 6.5 kg and length l = 2.1 m leans at an angle against a frictionless wall, Fig. 12-72. If the coefficient of static friction between the ladder and the ground is µs = 0.3, what is the minimum angle at which the ladder will not slip?
Saturday, March 15, 2014 at 3:51pm

Physics
A toy gun uses a spring to project a 6.1 g soft rubber sphere horizontally. The spring constant is 12.0 N/m, the barrel of the gun is 12.6 cm long, and a constant frictional force of 0.031 N exists between barrel and projectile. With what speed does the projectile leave the ...
Saturday, March 15, 2014 at 10:41am

Physics
A car of mass 1900kgs accelerates from rest to a speed of 27ms-1 in 8.1s.Calculate the average rate at which kinetic energy is supplied to the car during the acceleration.
Saturday, March 15, 2014 at 8:28am

physics
1) a bullet of mass 0.02 kg is fired into a block of wood of mass 1.5 kg resting on a horizontal table. The block moves offwith an initial speed of 8 m/s. Estimate the speed with the bullet strikes the block. 2) The bullet in question 1 is fired from a rifle of mass 2.5 kg. ...
Saturday, March 15, 2014 at 3:40am

Pages: <<Prev | 70 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | Next>>

Members