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Conservation of Momentum

Physic Problems

1. In a college homecoming competition, 16 students lift a sports car. While holding the car off ground, each student exerts an upward force of 400 N. (a) What is the mass of the car in kilograms? (b) What is its weight in pounds? 2. A person pushes on a block of wood that has been placed against a wall. Draw a free-body diagra

Elastic collission of two glass marbles

Two glass marbles moving along a straight line toward each other undergo an elastic collision. The speed of one marble is 2v and its mass is m; the speed of the other marble is v and its mass is 2m. What are the speeds and directions of the marbles after the collision?

Linear Momentum and Collision: Maximum spring compression, final velocities

Two particles with masses m1=2.0kg and m2=5.0kg are free to slide on a straight horizontal frictionless guide wire. The particle with the smaller mass is moving with speed of 17.0m/s and overtakes the larger particle, which is moving in the same direction with a speed of 3.0m/s. The larger particle has an ideal inertia-less spri

Newton's 3rd Law.

Newton's 3rd Law 1) The two forces in each pair may have different physical origins (for instance, one of the forces could be due to gravity, and its pair force could be a normal contact force). True / False? 2) The two forces of a 3rd law pair always act on different bodies. True / False? 3) Given that two bodies in

Rotational Forces - Spaceship

A space station shaped like a giant wheel has a radius of 105 m and a moment of inertia of 5.03 108 kgm2. A crew of 150 are living on the rim, and the station's rotation causes the crew to experience an apparent free-fall acceleration of g (Fig. P10.44). When 100 people move to the center of the station for a union meeting, the


Most of us know intuitively that in a head-on collision between a large dump truck and a subcompact car, you are better off being in the truck than in the car. Why? Many people imagine that the collision force exerted on the car is much greater than that experienced by the truck. To substantiate this view, they point out that th

Force, Collision and Conservation of Linear Momentum

A car (m1) is traveling at a velocity (v1) and it smashes into a wall. In situation 1: the car bounces off in a completely elastic collision with no change in speed. In situation 2: the car stops by inelastic collision. Which situation would be the most dangerous. Why? ----------------------------------------------------------


A 45.5 kg girl is standing on a plank that has a mass of 143 kg. The plank, originally at rest, is free to slide on a frozen lake, which is a flat, frictionless supporting surface. The girl begins to walk along the plank at a constant speed of 1.41 m/s relative to the plank. (a) What is her speed relative to the ice surface?


Block 1, of mass = 3.30, moves along a frictionless air track with speed = 31.0. It collides with block 2, of mass = 15.0 , which was initially at rest. The blocks stick together after the collision A.) Find the magnitude of the total initial momentum of the two-block system. Express your answer numerically. B.) Fi

Moment of inertia

Moment of inertia of a circular ring of mass M and radius a about a line through its centre perpendicular to its plane

Ignoring and Including Special Relativity

A satellite is at rest in space when destroyed by a hostile alien space ship. One piece that is 100 kg floats away at a speed of 0.80C. Another piece floats away with a speed of 0.90C away from the explosion in the opposite direction. What is the mass of the piece that flew away in traveling at 0.90C. Determine this two ways

Momentum of a Ball of Putty

A 3kg ball of putty moving at 1 m/s collides and sticks to a 2kg ball initially at rest. The putty and ball then move with a momentum of:

Conservation of Momentum and Collision Review

1. A car crashes into a wall at 25 m/s and is brought to the rest in 0.1 s. Calculate the average force exerted on a 75-kg test dummy by the seat belt. 2. A railroad diesel engine weighs four times as much as a freight-car. If the diesel engine coasts at 5 km/h into a freight-car that is initially at rest, how fast do the

Solving: Linear Momentum and Collisions

Problem: Two billiard balls of equal mass move at right angles and meet at the origin of an xy coordinate system. One is moving upward along the y axis at 2.0 m/s, and the other is moving to the right along the x axis with speed 3.8 m/s. After the collision (assumed elastic), the second ball is moving along the positive y axis.

Linear Momentum: Child in a Boat

A child in a boat throws a 6.00 kg package out horizontally with a speed of 10 m/s. Calculate the velocity of the boat immediately after, assuming it was initially at rest. The mass of the child is 24.0 kg and that of the boat is 50.0 kg.

More simple physics

A 0.025kg bullet traveling at 305m/s strikes a 1.500 kg ballistics pendulum hanging from a 2.00 m long string and buries itself in the block. How many degrees backward will the block swing? Do not use the law of conservation of momentum.

Propeller Flow - Momentum Equation

Consider a ducted propeller system, which is moving forward at a velocity V1. Analyse the system by assuming the duct remains stationary, as shown in the above diagram. If, for a specific design and point of operation, V2/V1=9/4 and V1/V2=5/4, then what is the thrust produced by the propeller in terms of the pressures at 2 and 3

Angular Momentum and COnservation of Angular Momentum

A uniform 2.45kg spinning disk with a radius of 0.243m is brought to rest by a brake pad pressed against the side 0.183m from the rotation axis. The wheels is brought to rest from an angular velocity of 15.4rad/s in a time of 24.3s. What frictional force was applied by the brake pad.

Collisions - Velocity and Direction

A 1500-kg car traveling due East at 30 m/s crashes into a 2000-kg vehicle heading North at 25 m/s, exactly in the center of an icy intersection and the two remain stuck together. Ignoring frictional forces, determine the initial velocity and direction of the crumpled vehicles immediately after the crash.

Weight of Boat

A man weighs 150lb and jumps onto a boat which is originally at rest. If he has a horizontal component of velocity of 3 ft/s just before he enters the boat, determine the weight of the boat if it has a velocity of 2 ft/s once the man enters it.

Speed of Cart

Two men A and B, each having a weight of 160lb, stand on the 200lb cart with wheels. Each man runs with a speed of 3 ft/s measured relative to the cart. Determine the final speed of the cart if a.) A runs and jumps off, then B runs and jumps off the same end, and b.) both run at the same time and jump off at the same time. Negle

Elastic and Inelastic Collisions and Momentum

For the attached problem set, the answers are included. The solution therefore should provide the work - how were the answers calculated? 7. The linear momentum of a runner in a 100-m dash is 7.5 * 10 kg * m/s. If the runner's speed is 10m/s, what is his mass? 13. A 15.0-g rubber bullet hits a wall with a speed of 150m/s.

Physics in Space: Conservation of Momentum

An astronaut performs maintenance work outside her spaceship when the tether connecting her to the spaceship breaks. The astronaut finds herself at rest relative to the spaceship, at a distance x1 from it. To get back to the ship, she decides to sacrifice her favorite wrench and hurls it directly away from the spaceship at a spe

One Dimensional Elastic Collision

A ball of mass 2 m is projected upward with speed Vo(or V=0)from the floor. Another ball of mass m is hung from the ceiling by a light string at a height h directly above the first ball, so that the projected ball collides with it. Derive an expression for the height about the floor to which the second ball will rise as a funct