Motion

Question 1

What is Newton’s first law of motion?

Answer 1

An object will continue in its present state of rest or motion unless acted on upon by an external resultant force

Question 2

So any object moving at a steady speed in a straight line has..

Answer 2

Zero resultant force acting on it

Question 3

What is inertia?

Answer 3

The inbuilt tendency for matter to resist any change in its motion

Question 4

What is Newton’s second law of motion?

Answer 4

If a resultant force (RF) act on an object of a mass (m), it causes an acceleration (a) in the direction of the resultant force

Question 5

What is the Newton’s Second Law equation for resultant force?

Answer 5

RF = ma
Newtons Kg m/s^2

Question 6

What is newtons third law of motion?

Answer 6

If object A exerts a force on object B, then object B exerts an equal and opposite force on A

Question 7

Any moving object has

Answer 7

Momentum

Question 8

What is the momentum equation?

Answer 8

Momentum = mass x velocity

Question 9

What is momentum measured in?

Answer 9

Newton seconds (Ns)
or kilogram metres per second (kgm/s)

Question 10

Momentum is a …… quantity.

Answer 10

Vector quantity

Question 11

How can Newton’s second law be written in terms of momentum?

Answer 11

RF = change in momentum/time taken
And can be written as:
RF = (mv - mu)/t

Question 12

If we ignore air resistance, the only force on an object in the air is

Answer 12

It’s own weight

Question 13

In the absence of other forces, all objects near the surface of the earth fall with the same …

Answer 13

acceleration- the acceleration due to gravity (g) also called the acceleration of free fall

Question 14

What is the size of the acceleration due to gravity on earth?

Answer 14

10m/s^2

Question 15

For any isolated system

Answer 15

The total linear momentum is constant

Question 16

What is an isolated system?

Answer 16

One upon which no external forces act

Question 17

What is the conservation of momentum?

Answer 17

Total moment before collision = total momentum after collision

Question 18

What is the equation for the conservation of momentum?

Answer 18

M1U1 +M2U2 = M1V1 + M2V2

Question 19

What is an elastic collision?

Answer 19

Where total kinetic energy is conserved

Question 20

What is inelastic collision?

Answer 20

Total kinetic energy before the the collision is greater than the total kinetic energy after the collision. Energy is lost as sound, heat etc

Question 21

What is a perfectly inelastic collision?

Answer 21

Kinetic energy is lost and the masses stick together after the collision

Question 22

What is the equation for a perfectly inelastic collision (stick together)?

Answer 22

m1u1 + m2u2 = (m1 + m2)v

Question 23

What is the definition of work?

Answer 23

Work (w) = Force applied (f) x distance moved (s) in direction of force

Question 24

What is the equation of work?

Answer 24

W=FS

Question 25

How much work is done if no motion occurs

Answer 25

No work is done

Question 26

What is energy?

Answer 26

The ability to do work

Question 27

What is energy measured in?

Answer 27

Joules

Question 28

What is the equation for kinetic energy?

Answer 28

K.E = 1/2 mv2

Question 29

What is the equation for gravitational potential energy?

Answer 29

P.E = mgh

Question 30

What is the principle of the conservation of energy?

Answer 30

Energy can never be created nor destroyed, it can only be changed from one form to another

Question 31

What is the link between work and energy?

Answer 31

Work done on or by an object = Energy gained or lost by an object

Question 32

What is power?

Answer 32

Rate of doing work

Question 33

What is the equation for power?

Answer 33

Power = Work done / Time taken P=W/t

Question 34

What is efficiency?

Answer 34

A way of describing how good a device is at transferring energy from one form to another in an intended way

Question 35

What is the equation for efficiency?

Answer 35

Efficiency = Useful energy out / Total energy in