Mechanics | Relativity Answers

An ideal spring of negligible mass with force constant of 400 N/m is placed on a frictionless horizonal

table with one end fixed at a wall next to the table. A billiard ball of mass 200 g is pushed against the spring, compressing the spring to some distance. After the system is released, the spring returns to equilibrium with the billiard ball leaving the table's edge at 4.00 m/s and hits the floor 80 cm below. Using the principle of energy conservation, (a) determine the initial compression of the spring. (b) What is the speed of the ball when it hits the floor?

A spherical asteroid has a radius of 500 km and the gravitational acceleration on the surface of the asteroid is 3 m/s?. (a) What is the minimum kinetic energy required for a 20 kg of object to escape from the asteroid? (b) At what speed will the object hit the surface of the asteroid if it is dropped from a height of 10 km?

a) As the meteor falls through the atmosphere the gravitational force continues to act on it. Suppose in a given instance the meteor is at a distance of 4000 km from earth. What would be the direction of the force that acts on it at that location?

b) Imagine it has approached near earth and now it is at a distance of 400 km from earth. What will be the direction of the gravitational force now?

When a meteor falls on earth across the earth's atmosphere there acts 3 forces on it. 2 of them are the gravity and the upthrust. Mention the third force.

When a meteor falls on earth across the earth's atmosphere there acts 3 forces on it. 2 of them are the gravity and the upthrust. Mention the third force.

Two crates, one with mass 4.00 kg and the other with mass 6.00 kg, sit on the frictionless surface of a frozen pond, connected by a light rope. A woman wearing golf shoes (so she can traction on the ice) pulls horizontally on the 6.00 kg crate with a force F that gives the crate an acceleration of 2.50 m/s^2. a) What is the magnitude of the force F? b) What is the tension in the rope connecting the two crates?

Abbey and Mia are in the basement playing pool. On Abbey's recent shot, the cue ball was moving east at 82 cm/s when it struck the slower 5-ball moving in the same direction at 24 cm/s. The 5-ball immediately speeds up to 52 cm/s. Determine the post-collision speed of the cue ball in cm/s.

Bailey is on the tenth frame of her recent bowling competition and she needs to pick up the last pin for a spare and the first place trophy. She rolls the 7.39 kg ball down the lane and it hits the 1.41 kg pin head on. The ball was moving at 7.9 m/s before the collision. The pin went flying forward at 1.7 m/s. Determine the post-collision speed of the ball.

An 108.0 kg boy and a 61.1 kg girl, both wearing skates face each other at rest on a skating rink. The boy and girl push each other, sending her eastward with a speed of 3.09 m/s. Determine the final velocity of the boy. Neglect friction.

A bicycle has a momentum of 24 kg m/s. What momentum would the bicycle have if it had…

… twice the mass and was moving at the same speed?

Answer 1

… the same mass and was moving with one-half the speed?

Answer 2

… three times the mass and was moving with twice the speed?

Answer 3

… one-half the mass and was moving with twice the speed?

Answer 4

… the same mass and was moving with twice the speed?

Answer 5

… three times the mass and was moving with one-half the speed?