Newton's Laws Of Motion

Question 1

What is newton’s first law of motion?

Answer 1

An object stays at rest or moves with constant velocity unless acted on by a force.

Question 2

What is required of the forces acting on an object moving at a constant velocity/at rest?

Answer 2

• Acted on by no forces

* Forces acting on it are balanced, and therefore the resultant force is zero

Question 3

What is the force proportional to?

Answer 3

Force is proportional to mass x acceleration

Question 4

What is the formula for force?

Answer 4

Force = Mass x Acceleration

Question 5

How is the formula for force derived?

Answer 5

By defining the unit of force, newton, the amount of force that will give an object with mass 1 kg an acceleration of 1kg, force being proportional to mass x acceleration can be written as:
Force = mass x acceleration

Question 6

What is newtons second law?

Answer 6

• Rate of change of momentum of an object is directly proportional to the resultant force applied to the object and is in the direction of the resultant force
resultant force = rate of change of momentum

Question 7

What is the formula for newton’s second law?

Answer 7

F = ma

Question 8

What is the formula and units for weight?

Answer 8

W = mass x gravity

Measured in newtons

Question 9

What are the forces on a body in equilibrium?

Answer 9

• Support force on it is equal and opposite to its weight.

Question 10

What is the gravitational field strength?

Answer 10

Force of gravity per unit mass on a small object at that position.

Question 11

What is inertia?

Answer 11

• Mass of an object is a measure of its inertia, which is its resistance to change in motion.
• More force is needed to give an object a certain acceleration than to give an object with less mass the same acceleration.

Question 12

What conclusions are gained from F = ma?

Answer 12

• More force you have acting a certain mass, the more acceleration you get
• For a given force the more mass you have, the less acceleration you get.

Question 13

What is the resultant force?

Answer 13

• Vector sum of all forces

* Measured in newtons

Question 14

What is newtons third law?

Answer 14

• If object A exerts a force on object B, then object B exerts and equal but opposite force on object A.

Question 15

Where does newton’s third law apply?

Answer 15

All situations and to all types of force, however both pairs of force area always the same type.