Theory
State Newton's 1st Law in common words.
An object in motion stays in motion until acted on by an outside force. An object at rest stays at rest until acted on my an outside force. (Inertia)
Find the momentum of a 6 kg bowling ball moving at 12 m/s.
72 kg m/s
Describe a perfectly inelastic collision.
Two objects collide and completely stick together. There is deformation and heat loss/production.
Describe a perfectly elastic collision.
No deformation or heat loss/production. Two objects bounce off of each other and kinetic energy is conserved. Think hard objects bouncing without shattering, like billiard balls or glass.
Calculating an explosion is like calculating a(n) ___________ collision in reverse.
inelastic
State Newton's 2nd Law in common words.
Force is proportional to mass time acceleration.
A brick experiences an impulse of 28 Ns. If this occurs from a 7 N force, how long is the force applied?
4 seconds
A 1 kg object moving at 3 m/s right hits a 5 kg object moving at 2 m/s right. If the objects stick together, find their final velocity?
2.17 m/s right
Block 1 (50 kg, 7 m/s right) elastically collides with block 2 (50 kg, stationary). What are the final speeds of the blocks?
Block 1: stationary
Block 2: 7 m/s right
State Newton's 3rd Law in common words.
Every action has an equal but opposite reaction.
Another phrase for impulse is:
a change in momentum
A 1 kg object moving at 3 m/s right hits a 5 kg object moving at 2 m/s left. If the objects stick together, find their final velocity?
1.17 m/s left
Sphere 1 is 25 kg and moving left at 2 m/s when it elastically hits sphere 2 (10 kg, 3 m/s right). If sphere 1 is moving 1.8 m/s right after the collision, what is sphere 2's final velocity?
6.5 m/s left
What are the 2 sure signs that a collision is inelastic?
Deformation, Heat production/loss
What is the equation for calculating impulse?
I = Ft
What is conserved in elastic collisions? What about inelastic?
Neither, Momentum, Kinetic Energy, Both
Elastic - both
Inelastic - Momentum
A 10 kg ball is rolling along with 100 kg m/s of momentum to the right. If a 5N force acts to the left on the ball for 6 seconds, how fast and what direction is the ball moving?
7 m/s right