Chapter 6: Momentum and Collisions
If a force is exerted on an object, one statement could be...
A small force applied over a long time interval can produce a large change in the object's momentum.
A moderate force will break an egg. Using the concepts of momentum, force, and time interval, explain why an egg is more likely to break when it is dropped on concrete than if it is dropped on grass.
An egg being dropped on grass has a greater amount of time to stop which decreases the impact force. The impact will be harder on concrete because the stopping time is shorter.
A child with a mass of 23 kg rides a bike with a mass of 5.5 kg at a velocity of 4.5 m/s south. Compare the momentum of the child with the momentum of the bike.
Neither the child nor the bike has momentum.
Is it possible for a spaceship traveling with constant velocity to experience a change in momentum? Explain.
No. The change in momentum equals the mass times the change in velocity. Since the change in velocity is zero, change in momentum will also be zero.
Whys is the sound produced by a collision evidence that the collision is not elastic?
The collision sound produced is evidence that energy escapes the collision (in the form of sound). In a perfectly elastic collision the energy of the two objects bounces them apart with force equal to what they had before the collision.
Two billiard balls of equal mass are traveling straight toward each other with the same speed. They meet head-on in an elastic collision. What is the total momentum of the system containing the two balls before the collision?
The total momentum of the system containing the two balls before the collision is zero.
A 75 kg person walking around a corner bumped into an 80 kg person who was running around the same corner. The momentum of the 80 kg person...
decreased.
In a two-body collision, what is conserved?
momentum is always conserved.
The two objects stick together and move with a common velocity after colliding. What type of collision is this?
perfectly elastic collision
Two balls of dough collide and stick together. What type of collision is this?
perfectly elastic collision
Two objects with different masses collide and bounce back after an elastic collision. Before the collision, the two objects were moving at velocities equal in magnitude but opposite direction. After the collision...
the less massive object had gained momentum.
When comparing the momentum of two moving objects...
the less massive object will have less momentum if the velocities are the same.
The law of conservation of momentum states that...
the total momentum of all objects interacting with one another remains constant regardless of the nature of the forces between the objects.