# Homework Help: Science: Physics

## Recent Homework Questions About Physics

**Physics**

a coin is placed on a stereo revolving at 33.3 revolutions per minute. what is its centripetal acceleration when it is placed 5 cm from the center of the turntable?

*Thursday, December 1, 2016 by Izzy*

**physics**

Calculate the kinetic energy of a tennis ball with a mass of 58g served by Andy Murray at 58 m/s

*Thursday, December 1, 2016 by bekyyyyyy*

**physics**

a stone is dropped from a height of 100 m. How long will it take to hit the ground? with what speed will it hit the ground?

*Thursday, December 1, 2016 by jason*

**Physics**

Find the orbital speed of a satellite in a circular orbit 3.70×107 m above the surface of the Earth. v = 3030 m/s So I've been trying to solve this problem for some time now and haven't figured it out. What I did is find orbital radius, use that to find the circumference of ...

*Thursday, December 1, 2016 by Alvin*

**physics**

the angular speed of the hour hand of a clock is

*Thursday, December 1, 2016 by jason*

**physics**

at any instant a car is observed to be moving at a velocity of 10 m/s. Five seconds later the car is found to be moving at a velocity of 20 m/s. how far did the car travel in 5 s?

*Thursday, December 1, 2016 by jason*

**physics**

an object of mass 10 kg is at rest when a net force of 20 N acts on it in a direction east. The acceleration produced on the object is? a) 2 m/s^2 in the direction east b) 2 m/s^2 in the direction west c) 0.5 m/s^2 in the direction east d) 0.5 m/s^2 in the direction west e) ...

*Thursday, December 1, 2016 by tim*

**physics**

A uniform beam weighing 1300N is attached to a vertical wall so that it is perfectly horizontal. the beam is 8 m long. A support race is anchored to the wall beneath the beam, making contact with the beam 3 m away from the wall at an angle of 25 degrees. the maximum force the ...

*Thursday, December 1, 2016 by kassy*

**physics**

A 1-kg rock is suspended from the tip pf a uniform meter at 0 cm mark so that the meter stick balances like a see-saw when the fulcrum is at 20 cm mark. what is the mass of the meter stick?

*Thursday, December 1, 2016 by tim*

**physics**

a car is slowing down while it is moving west. the direction on the car is ?

*Thursday, December 1, 2016 by jason*

**physics**

An object of mass 5 kg weighs 30 N on planet Z. The acceleration due to gravity on planet z is? a) 30 m/s^2 b) 10 m/s^2 c) 6 m/s^2 d) 0.17 m/s^2 e) 150 N

*Thursday, December 1, 2016 by Ray*

**physics**

It takes 5 seconds for a stone to fall to the bottom of a mine shaft. How deep is the shaft?

*Thursday, December 1, 2016 by Ray*

**Physics**

1. A photographer uses a camera lens with focal length of 50.0 mm to photograph a tree that is 4.60 m tall. She wishes to fill her 24.0-mm slide with the tree. (a) How far from the lens should the film be? 1/o + 1/24 = 1/50 600 + 25o = 24o o = -600/13 or -46.15 mm Therefore, ...

*Thursday, December 1, 2016 by Dylan*

**physics**

Probability of getting two heads among 4 coins for r = 0, 1, 2, 3, 4 find values of Pr, rPr, (r - r̄)2Pr and sum of r

*Thursday, December 1, 2016 by aregawi*

**SMCT Physics**

two force of 38N and 64N respectively act in the trunk pull it across the warehouse.if the angle between the force is 65. find its resultant and specify the angle it makes with the larger force?

*Thursday, December 1, 2016 by kent*

**physics**

Probability of getting two heads among 4 coins Complete the columns r Pr rPr (r - r̄)2Pr 0 1 2 3 4 sum

*Thursday, December 1, 2016 by aregawi*

**Physics**

If I have a solution of standard household vinegar and 3% peroxide mixed in equal parts and one drop is dropped through the sure how far must it fall before hitting an 80 degree steel plate to produce vaporization?

*Thursday, December 1, 2016 by BkB*

**Physics**

A uniform metre rule is balanced at the 35cm mark when a mass of 500g is placed at the 20cm mark .determine the mass of the rule ..

*Thursday, December 1, 2016 by Mariam*

**Physics**

A HeNe laser produces light with a wavelength of 632.8nm. The neon atoms, which emit the light, are moving at a mean velocity of 406m/s? a. What is the difference in the observed freq of light emitted from Ne atoms moving direction toward the exit mirror as opposed to those ...

*Thursday, December 1, 2016 by Meyoui*

**physics**

An object is projected at an angle of elevation of 45 degree with a velocity of 100m/s. Calculate it's range

*Wednesday, November 30, 2016 by anees*

**Physics**

Light of wavelength 469 nm passes through a slit, creating a diffraction pattern on a screen. The angular separation between the first diffraction minima on either side of the central maximum is 6.0∘ . Determine the width of the slit. I used this equation to solve for the ...

*Wednesday, November 30, 2016 by Po*

**physics**

A ship us heading north at 15 km/h in a tide moving at 6 km/h west ward. Determine the magnitude and direction of the resultant velocity of the ship.

*Wednesday, November 30, 2016 by Angelika*

**Physics**

A ship is heading north at 15km/h in a tide moving at 6km/h westward. Determine the magnitude and direction of the resultant velocity of the ship.

*Wednesday, November 30, 2016 by Zablanity*

**Physics**

During an adiabatic process, the temperature of 6.50 moles of a monatomic ideal gas drops from 525 °C to 169 °C. What is the work done? Here is my work, is it correct? T1 = 525+273 = 798 K T2 = 169 + 273 = 442 K work done = R[T2-T1]/1-gamma = 8.314[525 - 798]/(1-1.67) = - ...

*Wednesday, November 30, 2016 by Kayla*

**physics**

Suppose Captain Marvel leaps from the top of a 20 m tall building. If his initial speed is 12 m/s, then what is his speed just before he lands on the ground?

*Wednesday, November 30, 2016 by Mary*

**physics**

the speed of the train increased from 15 mi/hr to 25 mi/hr in distance of 500 ft. calculate the average acceleration in ft/s^2

*Wednesday, November 30, 2016 by Anonymous*

**Physics**

You set up a ramp with a length of 1.15 m, raising one end to a height of 0.4 m. You then roll a 0.300 kg toy car down the ramp, starting at rest a)What is the change in potential energy of the toy car rolling down this ramp? b)If all of that energy is changed into kinetic ...

*Wednesday, November 30, 2016 by A*

**Physics**

A ship is heading North at 15 km/h in a tide moving a 6 km/h westward. Determine the magnitude and direction of the resultant velocity of the ship.

*Wednesday, November 30, 2016 by Charlotte*

**Physics**

Gas is confined in a tank at a pressure of 11.0 atm and a temperature of 25.0 degrees C. If two-thirds of the gas is withdrawn and the temperature is raised to 75.0 degrees C, what is the new pressure of the gas remaining in the tank? Please help!

*Wednesday, November 30, 2016 by Anonymous*

**Physics**

A container is filled to a depth of 20cm with water. on top of the water floats a 30.0 cm thick layer of oil with specific gravity of 0.700, what is the absolute pressure at the bottom? Please help!

*Wednesday, November 30, 2016 by Anonymous*

**physics**

2. A wooden block slides directly down an inclined plane, at a constant velocity of 6 m/s. a. How large is the coefficient of kinetic friction if the plane makes an angle of 25º with the horizontal? 0.466 b. If the angle of incline is changed to 10º, how far will the block ...

*Wednesday, November 30, 2016 by abby*

**physics**

A 4.0 kg, 36-cm-diameter metal disk, initially at rest, can rotate on an axle along its axis. A steady 5.5 N tangential force is applied to the edge of the disk. What is the disk's angular velocity, in rpm, 4.0 s later?

*Wednesday, November 30, 2016 by Nathan*

**Physics**

Please help! Any advice is appreciated A water faucet in a house is h=8 m below the water surface in the local water tower. The radius of the orifice in the fully opened faucet is r=0.01 m. We assume non-viscous flow in this problem. a) How long does it take to fill a 20 liter...

*Wednesday, November 30, 2016 by Jamie*

**physics**

A ball is rolled off a table that is 1.25 meters tall and lands on the ground 0.48 meters away. If it took 0.505 seconds for the ball to land, what was the horizontal velocity of the ball? Record your answer to the nearest hundreth m/s (You do not need include units)

*Wednesday, November 30, 2016 by katy*

**Science physics**

A ship is heading north at 15km/h in a tide moving at 6km/h westward. Determine the magnitude and direction of the resultant velocity of the ship.

*Wednesday, November 30, 2016 by Anon*

**Physics**

A 4.05 x 10-2-kg block is resting on a horizontal frictionless surface and is attached to a horizontal spring whose spring constant is 121 N/m. The block is shoved parallel to the spring axis and is given an initial speed of 8.65 m/s, while the spring is initially unstrained. ...

*Wednesday, November 30, 2016 by BrookeNeed*

**Physics**

Derive an expression for kinetic energy of an object mass m moving with uniform velcoity v what happens to the kinetic energy of a body if its velcoity is halved?

*Wednesday, November 30, 2016 by Danial*

**Science Physics**

Derive an expression for kinetic energy of an object mass m moving with uniform velcoity v what happens to the kinetic energy of a body if its velcoity is halved

*Wednesday, November 30, 2016 by Danial*

**Science, physics**

A ship is heading north at 15km/h in a tide moving at 6km/h westward. Determine the magnitude and direction of the resultant velocity of the ship. I can't answer it because I don't get the formula. And please give me the formula. I need the answer later. I'll wait! Thankyou in...

*Wednesday, November 30, 2016 by Zablanity*

**Physics**

a 60-kg ice skater holds up a large sheet of cardboard that can catch the wind and drive her (frictionlessly) across the ice. while she's moving at 0.5m/s, a wind that is constant and horizontal for 5.0s exerts a forward force on the cardboard of 2.0 n. what is the skater's ...

*Wednesday, November 30, 2016 by Jocelyne*

**physics**

A particle of mass 1kg moving with initial velocity (i+2k)m/s is acted upon by a constant force(i+2j-2k)N,calculate the velocity and distance after 5s.

*Wednesday, November 30, 2016 by kazeem abiodun sikiru*

**Physics**

Do you think that power generated by the electric company means the same thing as the power as explained in this lesson (meaning work over time)? Why or why not? My teacher gave a hint to "Think about each in terms of the amount of work done" Please help! Thank you!!

*Wednesday, November 30, 2016 by Nathaly*

**Physics**

A 50-kg ice skater moves around a bend at 8 m/s. The radius of the bend is 8 m. Centripetal force is provided by friction between the blade of the skates and the ice. What is the amount of centripetal force?

*Wednesday, November 30, 2016 by Nolan*

**physics**

calculate the volume in cubic centimeters and area in square millimeters of a spherical bacterium of diameter 2.0um. model the bacteria is spheres

*Wednesday, November 30, 2016 by Sue*

**physics**

Suppose a river flows due south with a speed of 2.0 m/s. Given that speed of motorboat relative to water is 4.2 m/s due east. (a) In what direction should the motorboat head to reach a point on the opposite bank directly east from your starting point? (b) What is the velocity ...

*Wednesday, November 30, 2016 by Sue*

**Algebra**

A physics student stands at the top of a hill that has an elevation of 37 meters. He throws a rock and it goes up into the air and then falls back past him and lands on the ground below. The path of the rock can be modeled by the equation y = -0.02x^2 + 0.8x + 37, where x is ...

*Wednesday, November 30, 2016 by Mathew*

**Physics- Fluids**

Please help! Any advice is appreciated A water faucet in a house is h=8 m below the water surface in the local water tower. The radius of the orifice in the fully opened faucet is r=0.01 m. We assume non-viscous flow in this problem. a) How long does it take to fill a 20 liter...

*Wednesday, November 30, 2016 by Jamie*

**Physics**

Any help is appreciated! A grandfather clock is based on the period of oscillation of a pendulum. The clock keeps perfect time on the first floor of the Sears tower but when carefully moved to the top floor h=436 m above the surface of the earth, the clock is found to be slow...

*Wednesday, November 30, 2016 by Jamie*

**Physics**

An object is 3 cm tall is placed 24 cm from a converging lens.a real image is formed 8 cm from the lens.the focal length of the lens is

*Wednesday, November 30, 2016 by Swaleh*

**Physics**

An airplane is flying above the Earth's surface at a height of 10.9 km. The centripetal acceleration of the plane is 16.7 m/s2. What is the angular velocity of the plane moving in uniform circular motion? Take the radius of the earth to be 6400 km.

*Tuesday, November 29, 2016 by Uoit student*

**physics**

An airplane is flying above the Earth's surface at a height of 10.9 km. The centripetal acceleration of the plane is 16.7 m/s2. What is the angular velocity of the plane moving in uniform circular motion? Take the radius of the earth to be 6400 km. Please help, I've tried ...

*Tuesday, November 29, 2016 by Uoit student*

**Physics**

An ore car of mass 44000 kg starts from rest and rolls downhill on tracks from a mine. At the end of the tracks, 26 m lower vertically, is a horizontally situated spring with constant 4.5 × 105 N/m. The acceleration of gravity is 9.8 m/s 2 . Ignore friction. How much is the ...

*Tuesday, November 29, 2016 by Jack*

**Physics**

A 250kg rollercoaster cart loaded with people has an initial velocity of 3m/s. Find the velocity of the cart at part A (10m high), B (35m), and C (44m) Assume that friction is negligible.

*Tuesday, November 29, 2016 by Anna*

**Physics**

Not sure where to go with this problem, any help is appreciated! A bike is turned upside down for repairs. The front wheel can be described as a hoop with radius R=0.6 m and mass M=1.0 kg and a small point mass m=0.005 kg attached to the perimeter to represent the valve for ...

*Tuesday, November 29, 2016 by Jamie*

**Physics**

An iron ball of diameter 15.23cm rests on a brass ring of internal diameter 15.0cm at a temperature of 20 degrees celsius. To what temperature must both be heated for the ball to pass through the ring?

*Tuesday, November 29, 2016 by Onyi*

**physics**

why you expect the temperature of water at the bottom of Niagara falls to be slightly higher than the temperature at the top of the falls. Why?

*Tuesday, November 29, 2016 by Anonymous*

**physics**

so i created a graph Fe(N) vs. 1/r^2,so electric force vs the inverse squared of the radius.My slope was 9.21E-28, which was right. But what does the slope represent and how would I answer this question? a. Based on the slope of the line you created, determine the charge of ...

*Tuesday, November 29, 2016 by jon snow*

**physics**

a simple pendulum of lengh l,the mass of whose bob is m,is observed to have a speed v0 when the cord makes an angle theta0(0<theta<pi/2).In terms of g and the foregoing given quantities,determinate the least value v2 that v0 could have if the cord is to achieve a ...

*Tuesday, November 29, 2016 by laura*

**physics**

a simple pendulum of lengh l,the mass of whose bob is m,is obseved to have a speed v when the cord makes an angle with the vertical.Determine the least value v2 that v could have if the cord is to achieve a horizontal position during the motion

*Tuesday, November 29, 2016 by laura*

**Physics: HELP PLS**

The speed of a wave in a string is given by v = Ö(FT/m), where FT is the tension in the string and m = mass / length of the string. A 2.00 m long string has a mass of 15.5 g. A 93 g mass is attached to the string and hung over a pulley. The end of the string is then vibrated ...

*Tuesday, November 29, 2016 by Nopie*

**Physics**

Not sure where to go with this problem, any help is appreciated! A bike is turned upside down for repairs. The front wheel can be described as a hoop with radius R=0.6 m and mass M=1.0 kg and a small point mass m=0.005 kg attached to the perimeter to represent the valve for ...

*Tuesday, November 29, 2016 by Jamie*

**Physics**

A 42-kg box slides down a frictionless inclined plane. The angle of the inclined plane is 34.0 degrees. The distance from the box to the bottom of the inclined plane is 3 m. Draw the free body diagram of the force vectors acting on the box. Determine: a. The weight of the box ...

*Tuesday, November 29, 2016 by Anonymous*

**AP Physics**

Block A (mass 40 kg) and block B (mass 80 kg) are connected by a string of negligible mass as shown in the figure. The pulley is frictionless and has a negligible mass. If the coefficient of kinetic friction between block A and the incline is μk = 0.27 and the blocks are ...

*Tuesday, November 29, 2016 by Ashley*

**Physics**

Could someone please help walk me through this problem I'm struggling with? Thanks in advance! A brick with mass m1=2.5 kg can move without friction on a horizontal plane. The brick is attached to a wall by an ideal spring with spring constant k=2300 N/m. A second brick with ...

*Tuesday, November 29, 2016 by Jamie*

**Physics**

A stuntman drives a dirt bike on a curved track with a radius of 17.0 m. If he starts from rest and accelerates at 1.74 m/s^2, at what time will the magnitude of the total acceleration of the bike be 7.04 m/s^2?

*Tuesday, November 29, 2016 by Too Hard!!!!*

**PHYSICS**

A girl on a carousel has a centripetal acceleration of 21.3 m/s2. What is the acceleration of the girl if the carousel's angular velocity is doubled?

*Tuesday, November 29, 2016 by Anonymous*

**Physics**

Hi, I've been having trouble with this physics problem. I'm not sure where to begin. A brick with mass m1=2.5 kg can move without friction on a horizontal plane. The brick is attached to a wall by an ideal spring with spring constant k=2300 N/m. A second brick with mass m2=1.2...

*Tuesday, November 29, 2016 by Josh*

**physics**

When the experimental set up is immerse in water of refractive index n=1.5.what will be the charge in beta?

*Tuesday, November 29, 2016 by Amos*

**physics**

Dependence of fringe width on lamda D and d

*Tuesday, November 29, 2016 by Amos*

**physics**

A body at rest explodes into three equal parts, two parts after explosion fly off due north and west respectively with velocity 8m/s then calculate the magnitude and direction of velocity of 3rd pat.

*Tuesday, November 29, 2016 by san*

**physics**

When the wind is blowing an average of 31.8 mph, a wind tower with its propellors centered at a height of 80 m off the ground is supplied with energy at a rate of 14.4 kW. A large bank of batteries collects the energy from the wind tower. If the efficiency of each object (...

*Monday, November 28, 2016 by Brittany*

**Physics**

A Carnot engine of efficiency 41% operates with a cold reservoir at 24 °C and exhausts 1290 J of heat each cycle. What is the entropy change for the hot reservoir? Answer in J/K. I keep getting the answer incorrect. Here is the work: Efficiency = 100*(Th- Tc)/Th 41 = 100*(Th...

*Monday, November 28, 2016 by Kayla*

**Physics**

A cylindrically shaped piece of collagen (a substance found in the body in connective tissue) is being stretched by a force that increases from 0 to 0.0436 N. The length and radius of the collagen are, respectively, 2.90 cm and 0.0815 cm, and Young's modulus is 3.1 x 106 N/m2...

*Monday, November 28, 2016 by BrookeNeed*

**Physics**

A gun is shot horizontally from a building that is 10 meters high at a velocity of 220 meters/ second: I need to know what Vx is and Vy along with answering Vx after 3 seconds Vy after 3 second. We were given these equations Vy= Vy0-9.8t y= y0+Vy0t-4.9t^2 x=Vxt ,but I'm still ...

*Monday, November 28, 2016 by Anonymous*

**Physics, Math, Science**

A 56 kg student is standing atop a spring in an elevator that is accelerating upward at 3.5 m/s^2. The spring constant is 2300 N/m. By how much is the spring compressed? I'm not exactly sure how to approach this problem, much less solve it. The acceleration threw me off, as my...

*Monday, November 28, 2016 by Erik*

**Physics**

2. A ham sandwich consists of one slice of ham (7grams) and two slices of bread (25 grams each). You have 1kg of ham and 1kg of bread. You make as many as you can. How many sandwiches did you make? What is the mass of the sandwiches? What is the mass of the ingredients that is...

*Monday, November 28, 2016 by Katelyn*

**Physics**

1.Given that 1g of hydrogen combines completely with 8g of oxygen to form water, how much water can you make with 9g of hydrogen and 32g of oxygen?

*Monday, November 28, 2016 by Katelyn*

**Physics - Collisions**

A big toy school bus rear-ends a small toy school bus initially at rest. The bigger bus is several times heavier than the smaller one. Which of the following statements are true if the collision is totally inelastic? 1. The big bus exerts the same amount of force on the small ...

*Monday, November 28, 2016 by Kid*

**Physics**

What is the change in entropy of the lead when 2.0 kg of molten lead at its melting point temperature solidifies? For lead: L V = 207 kcal/kg at 1744°C, L F = 5.9 kcal/kg at 328°C. Express your answer using two significant figures in kcal/K

*Monday, November 28, 2016 by Sabrina*

**physics**

a sound generator is set up 5 m above the diving end of a swimming pool. the depth of the pool is known to be 12 m deep. the generator sends one short pulse of sound down at the pool. it takes 0.05s for an echo to return from the bottom of the pool.What is the speed of sound ...

*Monday, November 28, 2016 by kassy*

**physics**

a 7.0kg block and a 12kg block sit on a frictionless table. Between and touching, but not attached to, the blocks is a spring that is compressed by 13.5 cm. the spring has a spring constant of 1200 N/m. if the spring were released at what speed would each block move away.

*Monday, November 28, 2016 by kassy*

**Physics**

The figure shows a pV diagram of a gas for a complete cycle. During part bc of the cycle, 1190 J of heat flows into a system, and at the same time the system expands against a constant external pressure of 7.00 × 104 Pa as its volume increases from 0.0200 m3 to 0.0800 m3. ...

*Monday, November 28, 2016 by Sabrina*

**physics**

Just like the efficiency can be used to tell how 'good' an engine is, the Coefficient of Performance can be used to compare refrigerators. If a refrigerator requires 1.21×104 J of work to remove 3.23×104 J of energy from the inside of a refrigerator, what is the coefficient ...

*Monday, November 28, 2016 by taylor*

**Physics**

A military jet is flying at 224 m/s in a tight circular turn. If the military jet reaches a centripetal acceleration of 8.00 times the free-fall acceleration, what must the radius of its turn be?

*Monday, November 28, 2016 by Physics Lover*

**Physics**

A washing machine needs 17.9 s to speed up from rest to top speed of 5 rotation for every 2.78 s. If the damp cloths inside are 7.13 cm from the center, what is it's radial acceleration at top speed?

*Monday, November 28, 2016 by Physics Lover*

**Physics**

A few kids decide to go to the park to go on the merry-go-round. They are the only ones there so the merry-go-round is not moving yet. They push it for 6.00 s and it moves over an angle of 129°. What is the final angular velocity of the merry-go-round?

*Monday, November 28, 2016 by Plz*

**Physics**

How much faster would a person be moving if they stood on top of a 18.2 m high building compared to the ground? Take the period to be one day, and the radius of the earth to be 6400 km?

*Monday, November 28, 2016 by Impossible*

**physics**

A ball is attached to a spring on a frictionless horizontal surface. The ball is pulled to the right and released from rest at t = 0 s. If the ball reaches a maximum speed of 34.1 cm/s and oscillates with a period of 4.50 s, what is the ball's velocity at t = 0.350 s?

*Monday, November 28, 2016 by cristiano*

**Physics**

A 27.9 kg block (m1) is on a horizontal surface, connected to a 6.50 kg block (m2) by a massless string as shown in the figure below. The frictionless pulley has a radius R = 0.090 m and a moment of inertia I=0.060 kgm2. A force F = 192.1 N acts on m1 at an angle theta = 32.1...

*Monday, November 28, 2016 by Anonymous*

**physics**

A police van moving on a highway with a speed of 30km/hr, fires a bullet at a theif's car speeding away in the same direction with a speed of 192km/hr. If the muzzle speed of the bullet is 150m/sec. With what speed does the bullet hit the thief's car

*Monday, November 28, 2016 by Aarathana*

**Physics**

A 0.1134kg spherical meteor of diameter 3 cm enters the earth’s atmosphere at an elevation of 121920m with a velocity of 13411.2 m/s. The meteor’s temperature is -73.15˚C. The specific heat at constant volume (Cv) of the meteor is 800 J/kg˚C. (a) If the meteor has a ...

*Monday, November 28, 2016 by Jack*

**physics**

A pendulum clock has a pendulum shaft made of aluminum which has a coefficient of linear expansion of 24.0*10^-6K^-1. At 22 degrees celsius the period of the swing of the pendulum is 1.00seconds. If the temperature is reduced is reduced by 0.625°C every hour, how much time ...

*Sunday, November 27, 2016 by alicia*

**Physics**

A block of mass 2.5 kg hangs vertically from a frictionless pulley of mass 6.5 kg and radius 16 cm. Treat the pulley as a disk. Find: a) the acceleration of the block b) the tension in the rope I don't even know where to begin,

*Sunday, November 27, 2016 by Ana*

**Physics**

A torque of 50 N*m acts on a wheel of moment of inertia 25 kg*m^2 for 4 s and then is removed. b)How many revolutions does it make in 15 s if it starts at rest? I found the angular acceleration, 2 rad/s^2, but I don't know how to find the amount of revolutions.

*Sunday, November 27, 2016 by Ana*

**physics**

A block and tackle pulley system is used to lift a mass of 200 kg.if the machine has a velocity ratio of 5 and efficiency of 80%.sketch the possible arrangement of the system

*Sunday, November 27, 2016 by moses*

**physics**

Car A with a mass of 1000kg is travelling east at 25m/s when it collides with car B, 2000kg, travelling north at 15m/s. After the collision, the two cars stick together and have the same velocity. Assume that they slide without friction after collision. (a) What is the final ...

*Sunday, November 27, 2016 by Mable*

**Physics**

A bullet of mass 10g strikes a wooden block with velocity of 300m/s after penetrating 20cm into it, it's velocity drops to 200m/s. Then average resistance offered by the block is

*Sunday, November 27, 2016 by Appu*

**Physics**

An aluminum (with Young's modulus 7 x 10^10 Pa) rail is 88.0 m long and has cross-sectional area 0.00050 m^2. The rail is fixed at one end and a 4000 N force is applied at the other end. By how much does the bar stretch?

*Sunday, November 27, 2016 by Mary*

**Physics**

A brick of mass 2kg just begins to slide down an inclined plane at an angle of 45 degree with horizontal.what will be the force of friction

*Sunday, November 27, 2016 by Anonymous*

**Physics**

Block A, with a mass of 10 kg, rests on a 36.9° incline. It is attached to a string that is parallel to the incline and passes over a massless, frictionless pulley at the top. Block B, also with a mass of 10 kg, is attached to the dangling end of the string. The two blocks ...

*Sunday, November 27, 2016 by ANON*