# Homework Help: Science: Physics

## Recent Homework Questions About Physics

**Physics**

One object is thrown straight up at 54.9 m/s from the ground at the base of a building with is 157.9 meters tall. At the same time the object is thrown up at the bottom of the building, another object is thrown straight down at the top of the building. If both objects are to ...

**physics**

What is the moment of inertia of a triangular plate ABC of mass M and side BC=a about an axis passing through A and perpendicular to the plane of the plate.

**Physics**

You walk 1300m east and then 880m south in a total time of 16min . Compute your displacement. Enter the east and south components of the displacement separated by a comma. Compute your average velocity in m/s. Enter the east and south components of the velocity separated by a ...

**Physics**

A body of mass 20 kg moving with a velocity of 80 m/s collied with another body mass of 5 kg moving with a velocity of 50 m/s. If they move together after colision. Find common velocity.

**physics**

A soccer ball rolling across a field with an acceleration of -0.5m/s/s rolls 12.5 m and then comes to a stop after 8 seconds. What was the ball's initial speed?

**Physics**

A gamma ray with 700KeV energy is Compton-Scattered from an electron. Find the energy of the photon scattered at 110 degrees, the energy of the scattered electron, and the recoil angle of the electron.

**Physics**

If a 6.0keV photon scatters from a fee proton at rest, what is the change in the photon's wavelength if the photon recoils at 90 degrees?

**Physics**

White dwarf stars have been observed with a surface temperature as hot as 200,000 degree C. What is the wavelength of the maximum intensity produced by this star?

**physics**

If a stone is attached with a string and oscillates in to and fro motion then if the string cuts when the stone is at its highest position then what will be the path of the stone to be travelled

**Physics MCAT, Help please**

A box of mass m = 6kg slides with speed v = 4 m/s across a frictionless floor. It suddenly explodes into two pieces. One piece, with mass m1 = 2kg moves in the same direction with speed v1 = 8m/s. Find the velocity of the second piece. Its answer is 2 m/s , but I don't know ...

**Physics**

The biggest stuffed animal in the world is a snake 420 m long, constructed by Norwegian children. Suppose the snake is laid out in a park as shown in the figure below, forming two straight sides of a 114° angle, with one side 220 m long. Olaf and Inge run a race they invent. ...

**Physics of Modern Technology**

1) In a conventional explosion, when each molecule of high explosive chemically reacts, it produces about 4 x 10-18 J (joules) of energy. If each molecule of high explosive weighs as much as a single uranium 235 atom, and each uranium atom releases about 4 x 10-11 J in a ...

**physics**

An airplane with a speed of 53.8 m/s is climbing upward at an angle of 42° with respect to the horizontal. When the plane's altitude is 840 m, the pilot releases a package. (a) Calculate the distance along the ground, measured from a point directly beneath the point of ...

**physics**

Two canoeists start paddling at the same time and head toward a small island in a lake. Canoeist 1 paddles with a speed of 1.40m/s at an angle of 45 degrees north of east. Canoeist 2 starts on the opposite shore of the lake, a distance of 1.5 km due east of canoeist 1. A) In ...

**physics**

A book of mass 7 kg rests on a plank. You tilt one end of the plank and slowly increase the angle of the tilt. The coefficient of static friction between the book and the plank is 0.40. What is the maximum angle of tilt for which the book will remain stationary and not slide ...

**physics**

A flatbed truck is supported by its four drive wheels, and is moving with an acceleration of 7.4 m/s2. For what value of the coefficient of static friction between the truck bed and a cabinet will the cabinet slip along the bed surface?

**physics**

A spacecraft is traveling with a velocity of v0x = 5690 m/s along the +x direction. Two engines are turned on for a time of 845 s. One engine gives the spacecraft an acceleration in the +x direction of ax = 1.35 m/s2, while the other gives it an acceleration in the +y ...

**physics**

Two objects (53.0 and 16.0 kg) are connected by a massless string that passes over a massless, frictionless pulley. The pulley hangs from the ceiling. Find (a) the acceleration of the objects and (b) the tension in the string.

**physics**

A car is towing a boat on a trailer. The driver starts from rest and accelerates to a velocity of +11.4 m/s in a time of 29.2 s. The combined mass of the boat and trailer is 443 kg. The frictional force acting on the trailer can be ignored. What is the tension in the hitch ...

**physics**

A toboggan slides down a hill and has a constant velocity. The angle of the hill is 6.70° with respect to the horizontal. What is the coefficient of kinetic friction between the surface of the hill and the toboggan?

**physics**

worker stands still on a roof sloped at an angle of 30° above the horizontal. He is prevented from slipping by a static frictional force of 560 N. Find the mass of the worker.

**physics**

The longest pass in NFL history is approximately 83.7 m. Ignoring the effects of air resistance, calculate what must have been the initial speed of the football.

**physics**

If the earth doubled in mass but stayed the same size, what would be the acceleration due to gravity at the surface? m/s2 The dimensions of the earth as we currently know it are: Mass = 5.98E24 kg, Radius = 6.38E6 m and the universal gravitational constant = 6.67e-11 nm2/kg2

**physics**

If a ball hits a wall going 10 m/s, and bounces off going 7 m/s. What is the coefficient of restitution?

**physics**

You are riding a carousel that is turning at a constant angular velocity. You must pull toward the center with 100N of force to stay in place. You decide to move radially toward the center of the carousel to ride on a small animal figure that is at half the distance from the ...

**physics**

A spring with a spring constant of 53.0 N/m is attached to different masses, and the system is set in motion. What is its period for a mass of 2.7 kg?

**physics**

A basketball player throws the ball at a 60° angle above the horizontal to a hoop whose centre is located a horizontal distance L = 8.60 m from the point of release and at a height h = 0.80 m above it. What initial speed is required if the basketball is to reach the centre of...

**Physics**

A gamma ray with 700KeV energy is Compton-Scattered from an electron. Find the energy of the photon scattered at 110 degrees, the energy of the scattered electron, and the recoil angle of the electron.

**Physics**

If a 6.0keV photon scatters from a fee proton at rest, what is the change in the photon's wavelength if the photon recoils at 90 degrees?

**Physics**

A television tube operates at 20,000V. What is min wavelength for the continuous x-ray spectrum produced when the electrons hit the phosphor?

**Physics**

The Stanford Linear Accelerator can accelerate electrons to 50GeV (50x10^9eV). What is the minimum wavelength of photon it can produce by bremsstrahlung? Is this photon still called an x-ray?

**Physics**

An experimenter finds that no photo-electrons are emitted from tungsten unless the wavelength of light is less than 270nm. Her experiment will require photo-electrons of maximum kinetic energy 2.0eV. what frequency of light should be used to illuminate the tungsten?

**Physics**

What is the threshold frequency for the photoelectric effect on lithium (phi= 2.93eV)? What is the stopping potential if the wavelength of the incident light is 400nm?

**Physics**

How long does it take an automobile traveling 68.5 km/h to become even with a car that is traveling in another lane at 56.5 km/h if the cars’ front bumpers are initially 145 m apart? Answer in units of s.

**Physics**

An FM radio station of frequency 107.7MHz puts out a signal of 50,000W. How many photons/s are emitted?

**physics**

A person in a kayak starts paddling, and it accelerates from 0 to 0.577 m/s in a distance of 0.565 m. If the combined mass of the person and the kayak is 60.6 kg, what is the magnitude of the net force acting on the kayak?

**Physics**

White dwarf stars have been observed with a surface temperature as hot as 200,000 o C. What is the wavelength of the maximum intensity produced by this star? help please don't know what to do

**Physics**

A crate of mass 54 kg is attached to one end of a string, and the other end of the string runs over a pulley and is held by a person as in the figure below. If the person pulls with a force of 93 N, what is the crate's acceleration? (Assume that upward is the positive ...

**Physics**

Your friend is an environmentalist who is living in a tree for the summer. You are helping provide her with food, and you do so by throwing small packages up to her tree house. If her tree house is 21 m above the ground, what is the minimum (initial) speed you must use when ...

**Physics**

Two children are playing on a 147-m-tall bridge. One child drops a rock (initial velocity zero) at t = 0. The other waits 1.2 s and then throws a rock downward with an initial speed v0. If the two rocks hit the ground at the same time, what is v0?

**Physics**

Calculate the gravitational potential energy of the water in a lake of volume 100km^3 (mass=1.0x10^14kg). The lake has an average height of 50m above the hydroelectric generators at the base of the dam holding the water back.

**physics**

A rock dropped into a pond produces a wave that takes 15.7 s to reach the opposite shore, 24.3 m away. The distance between consecutive crests of the wave is 3.5 m. What is the frequency of the wave?

**Physics**

A hockey puck slides with an initial speed of 48 m/s on a large frozen lake. If the coefficient of kinetic friction between the puck and the ice is 0.030, what is the speed of the puck after 11 s?

**Physics**

A gamma ray with 700KeV energy is Compton-Scattered from an electron. Find the energy of the photon scattered at 110 degrees, the energy of the scattered electron, and the recoil angle of the electron.

**Physics**

If a 6.0keV photon scatters from a fee proton at rest, what is the change in the photon's wavelength if the photon recoils at 90 degrees?

**Physics**

A television tube operates at 20,000V. What is min wavelength for the continuous x-ray spectrum produced when the electrons hit the phosphor?

**Physics**

The Stanford Linear Accelerator can accelerate electrons to 50GeV (50x10^9eV). What is the minimum wavelength of photon it can produce by bremsstrahlung? Is this photon still called an x-ray?

**Physics**

An experimenter finds that no photo-electrons are emitted from tungsten unless the wavelength of light is less than 270nm. Her experiment will require photo-electrons of maximum kinetic energy 2.0eV. what frequency of light should be used to illuminate the tungsten?

**Physics**

What is the threshold frequency for the photoelectric effect on lithium (phi= 2.93eV)? What is the stopping potential if the wavelength of the incident light is 400nm?

**Physics**

An FM radio station of frequency 107.7MHz puts out a signal of 50,000W. How many photons/s are emitted?

**Physics**

White dwarf stars have been observed with a surface temperature as hot as 200,000 o C. What is the wavelength of the maximum intensity produced by this star?

**Physics**

A body's temperature is increased from 900K to 1900K. By what factor does the total power radiated per unit area increase?

**physics**

An airport has runways only 196 m long. A small plane must reach a ground speed of 38 m/s before it can become airborne. What average acceleration must the plane’s engines provide if it is to take off safely from its airport? Answer in units of m/s 2

**Physics**

A projectile of mass 0.377 kg is shot from a cannon, at height 6.6 m, as shown in the figure, with an initial velocity vi having a horizontal component of 6.1 m/s. The projectile rises to a maximum height of y above the end of the cannon’s barrel and strikes the ground a ...

**Physics**

Starting from rest, Mr.M's bus achieves a velocity of 25 m/s in a distance of 1.0 km. Find the time and the acceleration. I don't know which formula to use. Delta T = Vf - Vi / Aavg ?

**Physics**

A car is traveling at 72 km/hr. The driver begins to apply the brakes and the begins to slow with a constant acceleration (a). After the brakes are applied, the car stops in a distance of 100 m. What is the acceleration? My teacher gave the class a list of formulas but didn't ...

**Physics**

A motorcyclist traveling 35.0 m/s realizes suddenly that he is headed straight for the edge of the Grand Canyon 50.0 m away. He immediately begins to brake, decreasing his speed at a rate of 7.00 m/s^2. With what velocity will he fly off into the canyon?

**Physics**

A car enters the freeway with a speed of 7.2 m/s south and accelerates uniformly for 4.2 km in 4.0 min. How fast (in m/s) is the car moving after this time? I only need the formula. My teacher gave us a list but did not tell the class which equation is for which. Help please.

**Physics**

As you hurry to catch your flight at the local airport, you encounter a moving walkway that is 85 m long and has a speed of 2.2 m/s relative to the ground. If it takes you 68 s to cover 85 m when walking on the ground, how long will it take you to cover the same distance on ...

**Physics**

This is a vector problem. A man starts at home and runs 5 miles north and then 5 miles in a direction 23 degrees south of west. Now he wants to go back home in a straight line. How far does he need to go and in what direction? so i found that the hypotenuse equals 5.4 miles ...

**Physics**

A gamma ray with 700KeV energy is Compton-Scattered from an electron. Find the energy of the photon scattered at 110 degrees, the energy of the scattered electron, and the recoil angle of the electron.

**Physics**

If a 6.0keV photon scatters from a fee proton at rest, what is the change in the photon's wavelength if the photon recoils at 90 degrees?

**Physics**

A television tube operates at 20,000V. What is min wavelength for the continuous x-ray spectrum produced when the electrons hit the phosphor?

**Physics**

The Stanford Linear Accelerator can accelerate electrons to 50GeV (50x10^9eV). What is the minimum wavelength of photon it can produce by bremsstrahlung? Is this photon still called an x-ray?

**Physics**

An experimenter finds that no photoelectrons are emitted from tungsten unless the wavelength of light is less than 270nm. Her experiment will require photoelectrons of maximum kinetic energy 2.0eV. what frequency of light should be used to illuminate the tungsten?

**Physics**

An experimenter finds that no photo-electrons are emitted from tungsten unless the wavelength of light is less than 270nm.

**Physics**

What is the threshold frequency for the photoelectric effect on lithium (phi= 2.93eV)? What is the stopping potential if the wavelength of the incident light is 400nm?

**Physics**

An FM radio station of frequency 107.7MHz puts out a signal of 50,000 W.How many photons/s are emitted?

**Physics**

White dwarf stars have been observed with a surface temperature as hot as 200,000 o C. What is the wavelength of the maximum intensity produced by this star?

**Physics**

A body's temperature is increased from 900K to 1900K. By what factor does the total power radiated per unit area increase?

**Physics**

Q1-a stone is thrown upwards into the what is the magnitude and direction of its acceleration ? Q2-if a ball is thrown horizontally from a top of a cliff and takes 3 seconds to reach the beach below. Calculate the height if the cliff by considering the vertical motion only

**Physics**

Consider a wet roadway banked as in the following figure, where there is a coefficient of static friction of 0.30 and a coefficient of kinetic friction of 0.25 between the tires and the roadway. The radius of the curve is R = 50 m. (a) If the banking angle is 25o, what is the ...

**physics**

What's the momentum of a 3.5-kg boulder rolling downhill at 5 m/s?

**physics**

a 700 newton man is able to climb up 4.5 meters on a 6 meters ladder before it slips. What must be the coefficient of friction be if the ladder is arranged so that it makes an angle 50 degrees with the ground? Assume the ladder to be uniform and weighing 450 newtons.

**physics**

A piston of a car engine executes a simple harmonic motion. the acceleration a of the piston is related to its displacement x by the equation: a = -6.4*10^5x a) Calculate the frequency of motion b) The piston has a mass of 700 gms & a max displacement of 8 cm. Calculate the ...

**physics**

From a 5 metre high smooth hill a 6 kg block slides down and stops somewhere on the horizontal ground. Effect of turning part is negligible. Find the work done while the block is pulled back from this position to the top of the hill.

**Physics**

A golfball comes to rest 1.9 seconds after hitting a net. The force of the net slowed down at a rate of 56.3 m/s2. What was the velocity of the ball when it first hit the net??

**Physics**

Two friends, Barbara and Neil, are out rollerblading. With respect to the ground, Barbara is skating due south at a speed of 5.2 m/s. Neil is in front of her. With respect to the ground, Neil is skating due west at a speed of 3.2 m/s. Find Neil's velocity ((a) magnitude and (b...

**Physics**

An object is thrown upward from the top of a 10.0m high building at a speed of 10.0m/s. How fast is the object moving when it reaches the bottom of the building? The answer is 17.2 m/s but how?

**physics**

You are riding in the back of an open pick-up truck in the snow as you pass your friend's house. Despite the fact that it is snowing you know that he has a habit of being in his bedroom with the light on and his bedroom window open. Being as you are riding in an open truck in ...

**physics**

One of the methods used to train astronauts for the effects of "zero gravity" in space is to put them in a specially equipped plane which has been stripped of seats and fitted with padded walls. The pilot then takes the plane up to an altitude of typically 8600 meters and, at ...

**physics**

Your opponent, in a desperate attempt to return your wicked serve, makes a high lob of the tennis ball that causes it to land out of bounds on the asphalt course behind you. It then bounces so that it just barely clears a 3.90 m wall that is 2.32 m from where the ball hit the ...

**physics**

In the design of a rapid transit system, it is necessary to balance the average speed of a train against the distance between station stops. The more stops there are, the slower the train's average speed. To get an idea of this problem, calculate the time it takes a train to ...

**physics**

At serve, a tennis player aims to hit the ball horizontally. The height of the net is h=0.960 m, and server launches the ball from a height of H=2.20 m and a distance L=15.6 m from the net

**Physics Help Please!!!!**

a pitcher throws a softball horizontally from a height of 1.25 m and notes that it strikes the ground a distance of 15 m from the point where it was thrown. how long did it take the ball to reach the ground? what was the velocity at which the ball was thrown? what was the ...

**physics**

In a 100m race, Maggie and Judy cross the finish line in a dead heat, both taking 11.4s. Accelerating uniformly, Maggie took 1.80s and Judy 2.95s to attain maximum speed, which they maintained for the rest of the race. What was Maggie's acceleration?

**physics**

In the design of a rapid transit system, it is necessary to balance the average speed of a train against the distance between station stops. The more stops there are, the slower the train's average speed. To get an idea of this problem, calculate the time it takes a train to ...

**physics**

Instructions for finding a buried treasure include the following: Go 73.0 paces at 234°, turn to 135° and walk 122 paces, then travel 120 paces at 167°. The angles are measured counterclockwise from an axis pointing to the east, the + x direction. Determine the resultant ...

**Physics**

An ice skater skates 13.3 m southwest, then 26.6 m east, and finally 39.9 m in a direction 51.5◦ north of east. Find the magnitude of the displacement required to bring the skater back to her starting point. Answer in units of m

**physics**

What is the linear speed of Saturn in its orbit about the sun? Give your answer in meters per second. (Consider the orbit of Saturn to be a circle of radius 1.43×1012 m and that it takes 29.50 yr for one orbit around the sun.)

**physics**

As it passes over Grand Bahama Island, the eye of a hurricane is moving in a direction 60.7° north of west with a speed of 37.4km/hr. Two hours later, the course of the hurricane suddenly shifts due north and its speed slows to 21.0km/hr. How far from Grand Bahama is the eye ...

**physics**

A boy uses a slingshot to launch a pebble straight up into the air. The pebble reaches a height of 29.0 m above the launch point 3.3 seconds later. Assume air resistance is negligible.

**physics**

A ball is thrown directly downward with an initial speed of 3.08 m/s from a height of 14.6 m. After what interval does the ball strike the ground? The acceleration of gravity is 9.8 m/s 2

**physics**

A speeder passes a parked police car at a constant speed of 39.2 m/s. At that instant, the police car starts from rest with a uniform 2 is overtaken by the police car? Answer in units of s acceleration of 2.77 m/s . How much time passes before the speeder

**physics**

what is efficiency of carnot engine between the temperature of 100 degree centigrade and 60 degree centigrade

**Physics**

a frictionless mass1(1kg) is accelerated by mass two(1kg). The two masses are conceted by inextensible,flexible string. calculate the acceleration of the system of the two masses.

**college physics**

A 52.2 kg parachutist lands moving straight downward with a speed of 3.75 m/s. If the parachutist comes to rest with constant acceleration over a distance of 0.794 m, what force does the ground exert on her?

**physics**

The masses of these particles are mA = 374 kg, mB = 516 kg, and mC = 155 kg. d1 = 0.414 m and d2 = 0.207 m. Calculate the magnitude of the net gravitational force acting on particle A.

**physics**

A car has a mass of 1500 kg. If the driver applies the brakes while on a gravel road, the maximum friction force that the tires can provide without skidding is about 7000 N. If the car is moving at 18 m/s, what is the shortest distance in which the car can stop safely?

**physics**

A stone is dropped from peak of the hill. It covers a distance of 30 metres in the last second of its motion. Find the height of the peak?