Physics Forces

State the standard units for momentum

kgm/s

When a force arises between two objects, state which of the two interacting objects experience this force

Both the objects experience the force, equal in magnitude, but opposite in direction

A student wants to measure how the force applied to a toy car affects its acceleration. Outline a method to do this. Ensure the method would lead to valid results 

1. Set up apparatus as shown

2. Put 8 masses of 1N (100g) each on the mass hanger

3. Release cart and record acceleration from the light gate

4. Record accelerating force (N) and acceleration (M/S²) in a table

5. Take 1 mass of the car and add it to the cart

6. Repeat steps 3-5 six times

7. Plot graph F vs A, gradient is mass of cart + 800g

If an object is changing velocity, is there a resultant force acting on it

yes

State newtons 1st law

An object remains in the same state of motion unless a resultant force acts upon it

Give 3 examples of non-contact forces 

Gravitational force (weight), electrostatic force, magnetic force 

In terms of force, state the aim of safety features such as bike helmets, air bags, seat belts and crash mats

To increase the time it takes to change the momentum of an object, thereby reducing the force acting on the object

Sate newtons 3rd law

For every action there is an equal and opposite reaction. The two forces exerted are equal in size and opposite in direction

Define conservation of momentum

Total momentum before (event) = total momentum after (event)

Describe the mathematical relationship between the resultant force acting on an object and the acceleration of the object

The acceleration of an object is directly proportional to the resultant force acting on the object

If an object is travelled at a constant velocity, is there a resultant force acting on it 

no

Explain why vectors are represented as arrows 

They have both a size and direction 

Give 3 examples of a contact force

Friction, air resistance, normal contact force

Give the definition of force that links it to momentum

Force is the rate of change of momentum

State newtons 2nd law

Force is directly proportional to acceleration but inversely proportional to mass. So when a resultant force acts on an object it accelerates