Newton's Laws

What is Newton’s First Law?

‘an object will remain at rest or at a constant velocity unless it is acted upon by an external resultant force.’

What is definition of Weight?

The force of gravity acting on an object

What is the definition of Mass?

the amount of matter in an object

How can you calculate weight?

Weight = mass x gravitational field strength

What is the gravitational field strength on earth?

10N/Kg

What can newton’s second law be used to calculate?

The acceleration or deceleration

What is the equation for newton’s second law?

Resultant force = mass x acceleration

What does newton’s third law state?

‘if a body A exerts a force on body B, then body B exerts an equal and opposite force on body A.’

Name an example of newton’s third law?

A rocket pushes the exhaust gases backwards, so the gases will push the rocket forwards with the same force but opposite direction

What are the two forces that act on a sky diver?

Air resistance and weight

When the sky diver jumps out of a plane what happens to these forces?

Initially the air resistance is smaller than the weight, this causes the sky diver to accelerate.

As they increase what happens to the air resistance.

It increases

This stage continues until what happens to the forces?

This continues until the air resistance is equal and opposite to the weight

When the forces are balanced what does the sky diver continue to travel at?

Constant speed

What is constat speed known as?

As their terminal speed

When the sky diver opens their parachute the forces become what

The forces become unbalanced

What happens to the air resistance when the forces are unbalanced?

the air resistance increases to be larger than the weight this slows the sky diver down

As the sky diver slows the air resistance decreases to become what to the weight?

Become equal to weight

When the forces are balanced what is this called?

a new lower terminal speed