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Physics Questions and Answers

Explain how to measure the volume of an irregular shaped object if it floats in water.

How are impulse and momentum applied in an egg drop challenge? The challenge was to construct something protective out of 3 sheets of newspaper, tape, and 4 straws so the egg wouldn't break after a fall.

The position vector of a particle is given by r(t)=t^3*i+t^2*j. What are it's velocity speed and acceleration when t=2

You throw a basketball straight up into the air. Describe what happens to the kinetic energy and the gravitational potential energy of the ball as it moves up and back down until it hits the floor?

How fast must a ball be thrown upward to reach a height of 12 m?

What is the force constant of a spring cut in half, and would the frequency of SHM differ from the frequency of the same mass and energy? Clairification: If a uniform spring is cut in half, what is the force constant of each half, and how would the frequency of SHM using a half-spring differ from the frequency using the same mass and the same energy?

A layer of oil with density 800 kg/m^3 floats on of water with density 1000 kg/m^3. A block floats at the oil-water interface with 1/4 of its volume in oil and 3/4 of its volume in water. What is the density of the block.

Walking on pebbles in bare feet is more painful than walking on sand. Why?

Why is a parallel circuit arrangement best for house wiring?

A vertical spring stretches 10 cm under a load of 200 g. What is the spring constant, how much work is required to stretch the first 5 cm and the last 5 cm.  

Is a hockey stick used as lever? What kind of lever is it?

What is the secret to catching a water balloon without breaking it? Explain using physics.

A person is standing on a scale in a elevator accelerating downward. compare the reading on the scale to the person's true weight.

What is the formula for pressure?

Which of the following causes you to fall forward if you are standing in a moving bus, facing forward, and the bus comes to an immediate stop: A. the force due to kinetic friction between you and the floor of the bus. B. the normal force due to your contact with the floor of the bus. C. the force due to static friction between you and the floor of the bus. D. the force of gravity. E. No forces were acting on you to cause you to fall.

 1. A ray of light passes from air into water at an angle of 30.0 degrees. Find the angle of refraction. (22.1 degrees)

A force of 200 N acts on an area of 4 m^2. What is the pressure and what would be the pressure if the same force acted on half the area?

  Water has a density of 1000kg/m^3; what does this mean? What is its density in g/cm^3?  

Why is the current flow greater in a parallel circuit than it is in a series circuit?

In the context of conservation of energy what effect does friction have on kinetic energy and gravitational potential energy?

A bullet is fired horizontally out of a gun at the same time another is dropped from the end of the barrel. The one to hit the ground first is______ A) the bullet from the barrel because the distance its falls less   B)the bullet from the gun because its falls less distance   C) neither since they both fall the same distance at the same rate acceleration   D)the bullet from the gun because of gravity   E)the bullet from the gun because it go faster

A rope pulls a 2.0 kg bucket straight up, accelerating it from rest at 2.2 m/s^2 for 3.0 s. 1. Calculate the work done by each force acting on the bucket? 2. Calculate the net force acting on the bucket and the work done by the net force?

Why is it when a person is riding in the back seat of a forward-moving convertible with the top down, their hair blows forward instead of backward?

Can an object have kinetic energy and potential energy at the same time?

A 5 N force which acts along the direction vector (2,3) moves an object from A (1,3) to B (3,7).  Find the work done if the given units are metres.

Two long straight wires carrying the same current I and separated by a distance r exert a force F on each other. If the current is increased to 4I and the separation is reduced to r/6 what is the force between two wires?

A 145g baseball is thrown with a speed of 25m/s . How much work was done on the baseball to reach this speed if it started from rest.

What is the mass of air in a room measuring 5m X 10m X 10m?

A 73 kg skier coasts up a hill at 9.3 degrees to the horizontal. Determine how far along the... hill the skier slides before stopping, if the initial speed at the bottom is 4.2 m/s?

How does the Cosmic microwave background radiation support the Big Bang theory?

PHYSICS help If a metal wire has its length doubled and its diameter tripled, by what factor does its Young's modulus change?

A man inside an insulated metallic cage doesn't receive a shock when the cage is highly charged. Why?

A centrifuge, r = 0.06 cm, revolves at 24000 rpm. If its tensile strength is 120000 N, what is the maximum mass that it can hold?

Resultant of 100N 30 degrees E of N; 200N 80 degrees S of E; 150N 45 degrees S of W; 175N 25 degrees W of N and 50N towards North.

A 1800 kg car increases in velocity from 25m/s to 30m/s. How much work was done on the car to increase it to its final velocity.

Why do heavier things fall faster than lighter things if dropped from a certain height ?

What is the effect on the vertical height of the mercury column in a barometer of a) using a wider glass tube, b) pushing the tube further into the bowl, c) tilting the glass tube at an angle and d) taking the barometer to the top of a mountain? [ this is a question about the differentiation of barometer in 4 situations, so, please consider that as 1 question]

A small object with a momentum of magnitude 5 kg*m/s approaches head-on a large object at rest. The small object bounces straight back with a momentum of magnitude 4 kg m/s. What is the magnitude of the small object's momentum change in kg m/s?

What is a unit of mass?

A projectile is fired at an angle of 45 degrees to the horizontal. If its initial velocity is 90 m/s, how far does the projectile travel? (Assume g = 10m/s^2.)  

A hot-air balloon has just lifted off and is rising at the constant rate of 1.8m/s . Suddenly one of the passengers realizes she has left her camera on the ground. A friend picks it up and tosses it straight upward. If the passenger is 3.1m above her friend when the camera is tossed, what is the minimum initial speed of the camera if it is to just reach the passenger? (Hint: When the camera is thrown with its minimum speed, its speed on reaching the passenger is the same as the speed of the passenger.)

A 1.98 kg ball is attached to a ceiling by a 2.1 m long string. The height of the room is 5.95 m. The acceleration of gravity is 9.8 m/s2. What is the gravitational potential energy associated with the ball relative to the ceiling? Answer in units of J.

 What are the physiological effects of G-forces on the human body? I need to know what is happening to a person when they are experiencing G's at each G (1G, 2G, etc.). All the way up until they experience permanent bodily harm/damage, at what point is this, and at what point death will occur.  

A 3 kg stone is dropped from a height of 100 m . Find its kinetic and potential energies when it is 50 m from the ground.

A 2.2 kilo ohm resistor in a stereo system dissipates 42mW of power. What is the voltage across the resistor?

When a bird sings what form of energy is being transformed to what form? Is it potential energy to kinetic energy?

What is the angle of the ramp and speed of the block of ice in the following case: A 8.20 kg block of ice, released from rest at the top of a 1.10m long frictionless ramp, slides downhill, reaching a speed of 2.99m/s at the bottom. What is the angle between the ramp and the horizontal? What would be the speed of the ice at the bottom if the motion were opposed by a constant friction force of 10.2N parallel to the surface of the ramp?

A 10.2 cm diameter wire coil is initially oriented so that its plane is perpendicular to a magnetic field of 0.98 T pointing up.  During the course of 0.15 seconds, the field decreases to 0.10 T in the same direction.  What is the average induced emf in the coil?

A 28.0 kg crate is initially moving with a velocity that has magnitude 3.67 m/s in a direction 37.0 degrees west of north. How much work must be done on the crate to change its velocity to 6.25m/s in a direction 63.0 degrees south of east?

What is the energy of a quantum of light having a frequency of 6.0 x 10^14 hertz in electron-volts (eV)?