Monday

August 3, 2015

August 3, 2015

**science..physics**

An athlete runs from one end to the other end of a semicircular track whose radius is 70m.what is the total distance covered by the athlete and what is his displacement?
*Thursday, June 26, 2014 by tania*

**Physics**

A hydrogen atom is at the earth's surface. The electron and proton in the atom are separated by a distance of 5.29x10^-11m. What is the ratio of the magnitude of the electrical force exerted by the proton on the electron to the weight of the electron?
*Thursday, June 26, 2014 by jr*

**physics**

a body travel a distance of 15 m from a to b and them moves 20 m at right angles to ab. calculate total distance covered and displacement.
*Thursday, June 26, 2014 by gunjan*

**Physics**

Dina walked North and East and has a resultant displacement of 125, 35^0 East of North. She has a velocity of 2.5 m/s. Compute her walking time and average speed.
*Thursday, June 26, 2014 by Jade*

**physics**

The velocity of a sprinter is 9m / s. After 4 seconds, his velocity become zero. If acceleration is taken to be uniform. Find its value
*Thursday, June 26, 2014 by site*

**physics**

an object moves from point p to q with an average speed of 60m/s and comes back from point q to p with an average speed of 144km/h . what is the average speed of whole journey in m/s?
*Wednesday, June 25, 2014 by sanya*

**physics**

A 90 kg box is pushed by a horizontal force F at constant speed up a ramp inclined at 28°, as shown. Determine the magnitude of the applied force. when the ramp is frictionless. when the coefficient of kinetic friction is 0.18.
*Wednesday, June 25, 2014 by Anonymous*

**physics**

A sound wave of frequency 1310 Hz., propagating through air at 0 degrees Celsius, has a pressure amplitude of 11.0 Pa. What is the maximum particle speed (in meters/second)?
*Wednesday, June 25, 2014 by tom*

**physics**

A single constant force 18.1 N acts on a particle of mass 2.92 kg. The particle starts at rest at t=0. What is the instantaneous power delivered by the force at t=4.48s? Answer in units of W
*Wednesday, June 25, 2014 by Kaylee*

**physics**

A rain cloud contains 3.11 × 107 kg of water vapor. The acceleration of gravity is 9.8 m/s2 . How long would it take for a 1.8 kW pump to lift the same amount of water to an altitude of 20000 m? Answer in units of years
*Wednesday, June 25, 2014 by Kaylee*

**Physics**

A student gets his car stuck in a snow drift. Not at a loss, having studied physics, he attaches one end of a stout rope to the vehicle and the other end to the trunk of a nearby tree, allowing for a small amount of slack. The student then exerts a force vector F on the center...
*Wednesday, June 25, 2014 by Harley*

**physics**

A bird has a mass of 0.2 kg and is flying 10 m above the ground with a speed of 7 m/s. What is the total mechanical energy of the bird? Acceleration due to gravity is g = 9.8 m/s2.
*Wednesday, June 25, 2014 by Jesus *

**physics**

What is the acceleration of an object if it takes 10 seconds to increase its velocity by 40m/seconds?
*Wednesday, June 25, 2014 by Mary*

**Physics **

. A stone is dropped from the top of a building that is 500m high. Disregarding air resistance how long does it take the stone to reach the ground?
*Wednesday, June 25, 2014 by David*

**physics**

A car and driver weighing 7750 N passes a sign stating “Bridge Out 28.5 m Ahead.” She slams on the brakes, and the car decelerates at a constant rate of 10.6 m/s2 . The acceleration of gravity is 9.8 m/s2 . What is the magnitude of the work done stopping the car if ...
*Tuesday, June 24, 2014 by Kaylee*

**physics**

A spring with spring constant of 30 N/m is stretched 0.19 m from its equilibrium position. How much work must be done to stretch it an additional 0.077 m? Answer in units of J
*Tuesday, June 24, 2014 by Kaylee*

**physics**

A motor boat whose speed is 2.6 m/s in still water, needs to point upstream at an angle of 28.5 in order to travel straight across the river. Calculate the speed of the current and the resultant velocity of the boat across the river.
*Tuesday, June 24, 2014 by jane*

**Physics**

1. A person runs 800. m at an average speed of 6.00 m/s and then the next 800. m at an average speed of 8.00 m/s. Calculate (a) the total time of travel and (b) the average speed. 2. Sam travels by car from one city to another. He drives for 45.0 min at 95.0 km/h, 30.0 min at ...
*Tuesday, June 24, 2014 by Jade*

**Physics**

On the way to class, you walk north and then west such that your resultant displacement is 290 m in a direction 25deg west of north. Your average velocity is 2.0 m/s in the same direction as the displacement. Calculate (a) your walking time and (b) your average speed.
*Tuesday, June 24, 2014 by Jade*

**physics**

Match the process with the fundamental interaction responsible for this process. 1)A falling object slows down from a great speed to its terminal velocity. 2)An apple is held off the ground by the surface of a table.
*Tuesday, June 24, 2014 by hannah*

**physics**

A 236 kg block is released at a 4.2 m height as shown. The track is frictionless except for a portion of length 6.2 m . The block travels down the track, hits a spring of force constant k = 1483 N/m . The coefficient of kinetic fric- tion between surface and block over the 6.2...
*Tuesday, June 24, 2014 by jennifer*

**physics**

in a bag there are 20 red 30black 40 blue50 white balls. what is the minimum number of balls to be drawn without replacement so that you are certsin about getting 4 red,5 black,6 blue,7 white balls
*Tuesday, June 24, 2014 by nandhu*

**Physics**

A particle is moving along a straight line and its position is given by the relation x=( t3-6t2-15t+40)mm. Find:- (a). The time at which velocity is zero. (b). Position & displacement of the particle at that point. (c). Acceleration for the particle at that line.
*Tuesday, June 24, 2014 by Ram kumar*

**Physics**

A disgruntled physics student sees the front end of his teacher's car below him at the base of a building. If the student is 5.0 m high above the car which is 3.0 m long and traveling only 3m/s to the right, will the apple of the student hit the teacher's car? What is ...
*Tuesday, June 24, 2014 by VAN*

**Physics**

A disgruntled physics student sees the front end of his teacher's car below him at the base of a building. If the student is 5.0 m high above the car which is 3.0 m long and traveling only 3m/s to the right, will the apple of the student hit the teacher's car?
*Tuesday, June 24, 2014 by VAN*

**physics**

For a football player bending the ball around a defensive wall, state three principles which govern the flight path of the ball and the amount of spin imparted on to the ball? (3 marks) please help?
*Tuesday, June 24, 2014 by jamie *

**physics**

my physics teacher said that in simple harmonic motion of simple pendulum the direction of torque acting is opposite to angular displacement now i am wondering how ?as angular displacement is either anticlockwise or clockwise and torque direction is outward or inward to the ...
*Tuesday, June 24, 2014 by zoha*

**physics**

on his way to school,jed traveled 100 m north,300 m east,100 m north,100 m east,100 m north.
*Tuesday, June 24, 2014 by jp*

**physics**

A baseball pitcher throws a baseball horizontally at a linear speed of 50.6 m/s. Before being caught, the baseball travels a horizontal distance of 24.9 m and rotates through an angle of 54.5 rad. The baseball has a radius of 3.43 cm and is rotating about an axis as it travels...
*Monday, June 23, 2014 by Anonymous*

**physics**

Water is flowing into a factory in a horizontal pipe with a radius of 0.0223 m at ground level. This pipe is then connected to another horizontal pipe with a radius of 0.0400 m on a floor of the factory that is 10.6 m higher. The connection is made with a vertical section of ...
*Monday, June 23, 2014 by reuben*

**physics**

A 0.6 kg block of ice is sliding by you on a very slippery floor at 2.5 m/s. As it goes by, you give it a kick perpendicular to its path. Your foot is in contact with the ice block for 0.0035 seconds. The block eventually slides at an angle of 24 degrees from its original ...
*Monday, June 23, 2014 by sc*

**physics**

If you have 2 objects of diferrent densities and you want them to have equal masses,what ratio of the volume to each other The answer I think the object with the greater density must have low volume compared to the other with small density
*Monday, June 23, 2014 by Anonymous*

**physics (motion)**

the initial velocity of a particle is u (at t=0) and acceleration f is given by at.which relation is valid: (a)v=u+at^2 (b)v=u +at^2/2 (c)v=u+at (d)v=u
*Monday, June 23, 2014 by vivek*

**Physics--check answers please**

1. Resolve an acceleration vector of 40m/s^2 [25 degrees E of S] into its components For this I got 17 as my x component and 36 as my y component 2. A player is positioned 35m [40 degrees W of S] of the net. He shoots a puoock 25m [E] to a teammate. What second displacement ...
*Monday, June 23, 2014 by sandy*

**Physics I for College**

a rope that makes an angle of 30 degrees with the horizontal drags a crate along the floor. what must be the tension in the rope if a horizontal force of 40N is needed to drag the crate? please help me. i really didn't understand what my professor told me. he speak so fast...
*Monday, June 23, 2014 by Ian*

**Physics**

A 20 volt battery has a 4 ohm internal resistance. There is a 5 amp fuse in the main line of the battery. How many 6 ohm resistors can be connected in parallel across the battery before thefuse blows?
*Monday, June 23, 2014 by Chyna *

**physics**

The cricketer in the previous question hit the ball off the bat with a velocity of 25 m/s at an angle of 38° above the horizontal. If the boundary is 60 m away, work out whether the ball clears the boundary without bouncing or not. help please!
*Monday, June 23, 2014 by josh*

**physics**

A 78 kg volleyball player jumps and leaves the ground with a vertical velocity of 3.5 m/s. By thinking about the conservation of energy in a freefalling object, work out how high their centre of mass would reach at the top of their jump and present your answer to the nearest ...
*Monday, June 23, 2014 by josh*

**physics**

What is Coulombs law
*Monday, June 23, 2014 by Maheer*

**physics**

pls.. help me with this i really need it.. pls. A gas in a cylinder expands from a volume of 0.110 m3 to 0.320 m3. Heat flows into the gas just rapidly enough to keep the pressure constant at 1.65 x 105 Pa during the expansion. The total heat added is 1.15 x 105 J. (a) Find ...
*Monday, June 23, 2014 by acinad*

**physics**

Bar AB has length L, constant thickness d, and a width that tapers linearly from 3d at its fixed end (A) to d at its free end (B; see the figure below). The bar is homogeneous with mass density ρ and Young's modulus E. When hung vertically as shown in the figure, the ...
*Monday, June 23, 2014 by Donkey*

**physics**

Which equation would you use when you were describing a flowing viscous fluid? Select one: a. The Bernouilli Equation b. The Poiseuille Equation c. The equation of continuity d. And of the Equation of continuity or the Bernouilli Equation or the Poiseuille Equation.
*Sunday, June 22, 2014 by lisa*

**physics**

The definition of an incompressible fluid is Select one: a. A fluid with a constant density at all pressures b. A fluid with no viscosity c. A fluid with a constant pressure d. A fluid with viscosity
*Sunday, June 22, 2014 by lisa*

**Physics**

A heavier mass m1 and a lighter mass m2 are 20.5 cm apart and experience a gravitational force of attraction that is 8.60 10-9 N in magnitude. The two masses have a combined value of 5.80 kg. Determine the value of each individual mass.
*Sunday, June 22, 2014 by Lynn*

**Physics**

Two blocks connected by a string are pulled across a rough horizontal surface by a force applied to one of the blocks, as shown. The acceleration of gravity is 9.8 m/s2 . If each block has an acceleration of 5.2 m/s2 to the right, what is the magnitude of the applied force? ...
*Sunday, June 22, 2014 by Kaylee*

**Physics**

A string under a tension of 68 N is used to whirl a rock in a horizontal circle of radius 3.7 m at a speed of 16.53 m/s. The string is pulled in, and the speed of the rock increases. When the string is 0.896 m long and the speed of the rock is 71.5 m/s, the string breaks. What...
*Sunday, June 22, 2014 by Kaylee*

**Physics**

A plate carries a charge of -2.0 µC, while a rod carries a charge of +3.0 µC. How many electrons must be transferred from the plate to the rod, so that both objects have the same charge?
*Sunday, June 22, 2014 by Anonymous*

**Physics**

A plate carries a charge of -2.0 µC, while a rod carries a charge of +3.0 µC. How many electrons must be transferred from the plate to the rod, so that both objects have the same charge?
*Sunday, June 22, 2014 by Anonymous*

**Physics**

In the Bohr model of the hydrogen atom, the speed of the electron is approximately 2.45 × 106 m/s. Find the central force acting on the electron as it revolves in a circular orbit of radius 5.18 × 10−11 m. Answer in units of N
*Sunday, June 22, 2014 by Kaylee*

**Physics**

Zak, helping his mother rearrange the furni- ture in their living room, moves a 48.9 kg sofa 3.3 m with a constant force of 21 N. What is the work done by Zak on the sofa? Neglect friction. Answer in units of J
*Sunday, June 22, 2014 by Kaylee*

**Physics**

A 17.9 kg block is dragged over a rough, hor- izontal surface by a constant force of 74.1 N acting at an angle of angle 32.3◦ above the horizontal. The block is displaced 72.4 m and the coefficient of kinetic friction is 0.242. Find the work done by the 74.1 N force. The...
*Sunday, June 22, 2014 by Kaylee*

**physics**

An object dropped from a cliff falls with a constant acceleration of 10m/s2. Find its speed 2s after it was dropped? Solution:Given ,accelaration =10m/s time=2s speed=? therfore,speed=distance travelled\total time taken s=10\2=5(ans) . is it ok.
*Sunday, June 22, 2014 by Shalini*

**Physics**

a train travels the first 30 km of 120 km track with a uniform speed of 30km/h.What should be the speed of train to cover the remaining distance of the track so that its average speed is 60km/h for the entire trip
*Sunday, June 22, 2014 by Hitesh*

**Physics**

John exerts constant force of 120 N for 10 s. on a stalled motorcycle. The final velocity is 8 m/s after the force was applied. If original velocity was zero, what is a)change of momentum b) the impulse produced c) magnitude of the mass of motorcycle a&b) Impulse=deltaP=(120)(...
*Saturday, June 21, 2014 by Shontelle*

**physics**

Oil Flows through a horizontal cylindrical pipeline with an average speed of 1.2 m/s. The pipeline has a radius of 0.5 metres. Calculate the volume of oil (in cubic metres) which flows through this pipeline in one hour.
*Saturday, June 21, 2014 by muller*

**physics**

Calculate the speed of water (in m/s) flowing from a pipe at the bottom of an open topped barrel which has a water level 138 cm high in it.
*Saturday, June 21, 2014 by allen*

**physics**

A sound registers 77.9 decibels on a detector. What is the intensity in W/m2? Assume the threshold of human hearing is 1.0×10-12 W/m2. Give your answer in picowatts/m2. 1 pW = 1×10-12 W/m2
*Saturday, June 21, 2014 by allen*

**physics**

Calculate the speed of a wave in m/s along a taut string with tension 139 Newtons and a mass per unit length of 3.6 grams per metre.
*Saturday, June 21, 2014 by allen*

**Physics**

A dart gun where you compress the spring and it shoots a rubber dart of a mass 0.122 kg. The dart is shot vertically and gains 2.50 m. a) what speed did the dart leave the toy gun? b) If the spring is compressed 0.125 m what is the elasticity coefficient of the spring?
*Saturday, June 21, 2014 by Michel*

**physics**

a stone is projected upward with a speed of 80.0ft/s from a 224 ft tower. find the maximum height and the speed at which it strikes the ground.
*Saturday, June 21, 2014 by roger*

**Physics**

An airplane is flying due south with a velocity of 26.0 m/s. a. If there is a tailwind of 27.0 m/s, what is the magnitude and direction of the actual velocity of the airplane? (a tailwind blows in the same direction as the motion of the airplane) b. If there is a headwind of ...
*Saturday, June 21, 2014 by sci-physics*

**physics**

12 equal wires of same rasistance R are joined to form a cube. Find the total rasistance between corners of same edge of cube
*Saturday, June 21, 2014 by maggi*

**Physics**

A stone is dropped from a height of 50 m above the ground will it has a uniform or a non-uniform speed as it moves towards the ground.
*Saturday, June 21, 2014 by Rajkumar*

**physics**

a car accelerates with an acceleration of 2m/s2 for 5secs what is its final velocity at the end of 5secs if its initial velocity is 40m/s?
*Saturday, June 21, 2014 by gutema *

**Physics-half way fin.**

A person was shot vertically upward from a cannon with a mass 52 kg and a speed of 35 m/s. a) what was the height according to conservation of energy and b) what was the person's total energy? (TME never changes!) a) used TMEo=TMEf height= 63 m. b.)Would I use PE=mgh
*Saturday, June 21, 2014 by Sasha*

**physics**

What is the difference b/w longitudinal wave and transverse wave ?
*Saturday, June 21, 2014 by ravi*

**ap physics**

A golfer sees the green (where the hole is) at a distance of 120.0 m at heading 75.0° north of west. She also sees her teammate at a distance of 60.0 m and heading 15.0° north of east. What distance and direction would her teammate have to land the ball to hit the ...
*Saturday, June 21, 2014 by mindi*

**Physics**

A car is moving at 50 miles per hour. The kinetic energy of that car is 5 × 105 J. How much energy does the same car have when it moves at 114 miles per hour? Answer in units of J
*Friday, June 20, 2014 by Kaylee*

**ap physics**

A golfer sees the green (where the hole is) at a distance of 120.0 m at heading 75.0° north of west. She also sees her teammate at a distance of 60.0 m and heading 15.0° north of east. What distance and direction would her teammate have to land the ball to hit the green?
*Friday, June 20, 2014 by iz*

**general physics**

what are the differences between polygon and parallelogram method?
*Friday, June 20, 2014 by krissy*

**physics**

A 2.40 kg firecracker explodes into two pieces and produces 170 J of heat, light, and sound energy. One of the pieces has a mass of 0.800 kg and a speed of 4.50 m/s after the explosion. If the mass of the other piece is 1.20 kg, what is its speed after the explosion?
*Friday, June 20, 2014 by Martin*

**Physics**

A daredevil decides to jump a canyon of width 6.5 m. To do so, he drives a motorcycle up an incline sloped at an angle of 9.45◦. The acceleration of gravity is 9.8 m/s2 . What minimum speed must he have in or- der to clear the canyon? Answer in units of m/s
*Friday, June 20, 2014 by Kirbi*

**Physics-check plz**

If a pitcher throws a fast ball with a speed of 35 m/s. The ball has a mass of 220 grams. a) how much work was done in throwing the ball? b) If the catcher catches the ball by moving his mitt 15 cm. backward what force did he exert? a.) Throwing the ball in a positive ...
*Friday, June 20, 2014 by Sasha*

**physics**

a rock is thrown vertically down from a bridge with an initial velocity of 30m/s and strikes the water in 2.0sec. find the velocity with which the rock strikes and the height of the bridge.
*Friday, June 20, 2014 by roger*

**physics**

a stone is thrown straight upward and rises to a maximum vertical height of 40.0m. with what velocity was it thrown and how long does it take for the stone to return to the initial level from which it was thrown?
*Friday, June 20, 2014 by roger*

**physics**

a steel ball dropped from a tower strikes the ground in 3.0 seconds. Find the velocity with which the ball strikes the ground and the height of the tower in meters.
*Friday, June 20, 2014 by roger*

**physics**

if a bird is sitting on a seat in a plane that is travelling 300 km/h[E], if the bird jumps for a couple seconds will he: land on the front of the bus, back of the bus, one seat ahead, one seat behind, on the same seat he was standing on
*Friday, June 20, 2014 by sally*

**physics**

In space, an object has only ONE force acting on it. Can the object have constant acceleration and/or a velocity of 0. Explain.
*Friday, June 20, 2014 by sally*

**physics**

In a vacuum, a stone and feather fall at the same time. Can you make the assumption that the acceleration of gravity acting on both objects is the same? Explain.
*Friday, June 20, 2014 by sally*

**physics**

1)if y=e^x . cot x then dy/dx will be 2) f(x)=sin²x-cos²x then the value of f' (π/4)
*Friday, June 20, 2014 by karan*

**physics**

1)if y=x³+2x²+7x+8 then dy by dx will be- 2) if y= 1/x⁴ then, dy by dx will be: 3) if y = x² sin x, then dy/dx will be-
*Friday, June 20, 2014 by karan*

**physics**

1) y=4+5x + 7x³. Find dy/dx 2) if y= tan x cos²x then dy by dx will be-
*Friday, June 20, 2014 by karan*

**physics**

1)Y=x+x².+1/x+1/x³ find dy by dx 2)y=x²+1/x². Find dy by dx
*Friday, June 20, 2014 by karan*

**physics**

1.∫ x³(x+1)dx 2.∫ (1-cot²x)dx 3.∫ cosx(tan x + sec x) dx 4.∫ dx/√5x+8 using u= 5x+8 and using u= √5x+5
*Friday, June 20, 2014 by karan*

**PHYSICS**

'if diametre of earth is reduced to half mass remains constant what is then duration of day and night'
*Friday, June 20, 2014 by AYESHA*

**physics**

at the start of a race , a horse accelerates out of the gate at a rate of 3.00m/s squared. how long does it take the horse to cover the first 25.0m of the race?
*Friday, June 20, 2014 by roger*

**physics**

a car travel with a uni form velocity of 25m/s for 5& the brak over then applied and the car coms the rest wirh a uniform retar in fyrther 10s draw ut grph and use it to find 1 distance covered 2 the reatardation
*Friday, June 20, 2014 by ramesh*

** college physics **

An ultrasonic motion sensor sends very short pulses for ultrasound to measure the distance to an object . The sensor cannot send another pulse until the echo form the previous pulse is detected. What is the maximum possible number of individual measurements per second if the ...
*Thursday, June 19, 2014 by sharon*

**physics**

Find the work done by 2.32 moles of an ideal gas if its volume doubles at a constant temperature of 22.6°C.
*Thursday, June 19, 2014 by Anonymous*

**physics**

what air speed and heading would enable a plane to travel [NE] with a ground speed of 275 km/h if there is a wind blowing at 55 km/h from the south?
*Thursday, June 19, 2014 by joy*

**physics**

A proton has mass 1.7×10−27 kg. What is the magnitude of the impulse required to increase its speed from 0.995c to 0.998c? magnitude of impulse = i used mv=vectorp i dont know what to do from there
*Thursday, June 19, 2014 by sc*

**physics**

A 100-kg object is lifted to an altitude of 1000 km. What is the weight of the object on the ground? Does it have the same mass and weight at 1000 km? Explain.
*Thursday, June 19, 2014 by Gene*

**physics**

1.∫ x³(x+1)dx 2.∫ (1-cot²x)dx 3.∫ cosx(tan x + sec x) dx 4.∫ dx/√5x+8 using u= 5x+8 and using u= √5x+5
*Thursday, June 19, 2014 by karan*

**Physics**

You have a grindstone with a mass of 90.0 kg, 0.340-m radius, and is turning at 90.0 rpm. You press a steel ax against it, bringing it to a stop in 36.0 s. (a) What is the change in kinetic energy of the grindstone? (b) If the tangential force due to the friction between the ...
*Thursday, June 19, 2014 by Anonymous*

**physics**

1.∫ csc (u-π/2) cot (u-π/2) du. 2.∫ sec^2(3x+2)ds 3.∫ √3-2s ds 4. ∫ 12(y^4+y4y^2+1)^2 (4^3+2y) dy use u= y^4+4y^2+1
*Thursday, June 19, 2014 by karan*

**physics**

A ball is thrown vertically upwards and returns to its initial position in 6.0 second. What is its initial speed
*Thursday, June 19, 2014 by afiqa*

**Physics**

Consider a car starting at rest at the beginning of a 250 m street. At time t = 2.0 s it is 20 m along the street. At time t = 4.0 s it is 80 m along the street. Find its average velocity in the: (a) First 2.0 s (b) First 4.0 s (c) Last 2.0 s My work: I have done 2 question a ...
*Wednesday, June 18, 2014 by Long*

**Physics**

a boat leaves shore and travels 30km east and then 15km 50 degree South of east Find the resultant the boats resultant displacement?
*Wednesday, June 18, 2014 by Earl *

**Physics**

1. A person runs 800. m at an average speed of 6.00 m/s and then the next 800. m at an average speed of 8.00 m/s. Calculate (a) the total time of travel and (b) the average speed. 2. A boy kicked a can horizontally from a 6.5 m high rock with a speed of 4.0 m/s. How far from ...
*Wednesday, June 18, 2014 by Piper*

**physics**

an electric hot water heater takes in cold water at 13.0 degrees celsius and delivers hot water. the hot water has a constant temperature of 45 degrees celsius when the "hot" faucet is left open all the times, and the volume flow rate is 5.0 x 10 ^-6 m^3/s. what is ...
*Wednesday, June 18, 2014 by Anonymous*