Module 3 - Chapter 7 - Laws of motion and momentum

Question 1

What is Newton’s first law of motion?

Answer 1

Newton’s first law of motion states that an object will remain at rest or continue to move with a constant velocity unless acted upon by a resultant force.

Question 2

What is Newton’s 2nd law of motion?

Answer 2

Newton’s 2nd law of motion states that the resultant force acting on an object is directly proportional to the rate of change of its momentum, and is in the same direction.

Question 3

What is Newton’s 3rd law of motion?

Answer 3

Newton’s 3rd law of motion states that when 2 objects interact, they exert an equal and opposite force on each other.

Question 4

What are the 4 types of interactons?

Answer 4

Gravitational
Electromagnetic
Strong nuclear
Weak nuclear

Question 5

State the equation for momentum

Answer 5

p = mv
momentum = mass x velocity

Question 6

What is the unit for momentum?

Answer 6

kg m/s

Question 7

What is the principle of conservation of momentum?

Answer 7

For a system of interacting objects, the total momentum in a specified direction remains constant, as long as no external forces act on the system.

Question 8

What are the two types of collisions?

Answer 8

Perfectly elastic and inelastic

Question 9

What is the difference between an inelastic and a perfectly elastic collision?

Answer 9

In both collisions, both energy and momentum are conserved due to conservation of energy and momentum. However, in an inelastic collision, the total kinetic energy is not conserved whereas it is in a perfectly elastic collision.

Question 10

State the equation for Newton’s 2nd law of motion

Answer 10

F = Δp/Δt
net force = change in momentum / time

Question 11

What is impulse?

Answer 11

The impulse of a force is the product of a force and the time in which a force is acting on an object.
Therefore, impulse = change in momentum

Question 12

What is the unit for impulse?

Answer 12

Ns or kg m/s

Question 13

What does the area under a force-time graph represent?

Answer 13

The area under a force-time graph represents the impulse.
Therefore, impulse = Ft

Question 14

What happens when 2 identical objects collide obliquely?

Answer 14

They go off in separate directions perpendicular to each other (90 degrees).

Question 15

What happens to the total momentum after the collision?

Answer 15

The total momentum should stay the same after the initial impact due to the conservation of momentum.

Question 16

What is the equation to resolve momentum in the horizontal direction for 2 objects colliding?

Answer 16

total initial = total final
m₁u = m₁v₁cosθ₁ + m₂v₂cosθ₂

Question 17

What is the equation to resolve momentum in the vertical direction for 2 objects colliding?

Answer 17

total initial = total final
m₁u = m₁v₁sinθ₁ + m₂v₂sinθ₂