Newtons laws

Question 1

Newtons 1st Law

Answer 1

Law of inertia = an object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless an unbalanced force acts upon it.

Question 2

Inertia

Answer 2

the resistance an object has to change in its state of motion.

Question 3

Exam question ‘‘explain how newtons first law of motion applies to this swimmer (4)’’

Answer 3

1. newtons first law is the law of inertia, the swimmer will remain still or in constant motion unless a force is applied.
2. the force is applied by muscles, rectus femurs contraction to extend the knee and push off the block.
3. performer stays in a current state until another force is applied, in this case the water would overcome her inertia and slow the swimmer down.
4. at this time, she would need to apply another force after hitting the water to accelerate in the water.

Question 4

Newtons 2nd law

Answer 4

Law of acceleration - the rate of momentum of a body is proportional to the force causing it and takes place in the direction in which the force acts. (force = mass x acceleration)

Question 5

Exam question = ‘‘explain how newtons second law of acceleration can be applied to a 400m runner (4)’’

Answer 5

1. Newtons second law of acceleration is explained as force = mass x acceleration.
2. mass is constant and in order to accelerate a greater force must be produced to move the mass.
3. force is produced by the muscles
4. greater the contraction the greater the force leading to greater acceleration in the direction in which the Force has been applied

Question 6

Newtons 3rd law

Answer 6

Law of action/reaction - for every action there is an equal and opposite reaction.
eg = a high jumper pushing up off the ground and the ground pushes back with an equal force.