Chapter 7, Laws of motion and momentum.

Question 1

What is Newtons first law of motion?

Answer 1

An object will remain at rest or continue to move with constant velocity unless acted upon by a resultant force.

Question 2

What is Newtons second law of motion?

Answer 2

The net force acting on an object is directly proportional to the rate of change of its momentum and is in the same direction (or in the SI system F = Δp/Δt and when mass is constant F = ma).

Question 3

What is Newtons third law of motion?

Answer 3

When two objects interact they exert equal and opposite forces upon each other.

Question 4

What is the equation for momentum?

Answer 4

p = mv (momentum = mas * velocity).

Question 5

What conservation law can you use to predict the outcome of a collision (with what assumptions)?

Answer 5

Conservation of momentum assuming there are no external forces (closed system).

Question 6

What is/isn’t conserved in perfectly elastic and elastic collisions?

Answer 6

In an inelastic collision momentum and total energy are conserved but kinetic energy is not. In a perfectly elastic collision all these quantities are conserved.

Question 7

Defining equation for impulse?

Answer 7

The product of force and the time for which this force acts (change in momentum).

Question 8

What physical quantity is given by the area under a force-time graph?

Answer 8

Impulse.