P2 Forces And Motion

Question 1

Resultant force

Answer 1

Total force

40N -> [object]

Question 2

Momentum

Answer 2

Is a vector
Calculation: m = P/v
M = mass, v = velocity, p = momentum
Measured in Kgm/s(kilogram meters/second)

Question 3

Resultant force formula

Answer 3

mv-mu mv = final momentum, mu = starting momentum
———
F*t

Question 4

Newton’s first law

Answer 4

An object will move at a constant speed unless an external force acts upon it

Question 5

Centripetal force

Answer 5

The resultant force which causes an object to move in a circle, changing its velocity but not speed. E.g. provided by wires on a chairoplain

Question 6

Mass, weight, gravity formula

Answer 6

M = W/G

Question 7

Acceleration due to gravity on earth

Answer 7

10 m/s^2

Question 8

Newton’s second law

Answer 8

Force = mass * acceleration

Question 9

Newton’s third law

Answer 9

For every action there is an equal and opposite reaction

Question 10

Differences between action-reaction and balanced forces

Answer 10

Action-reaction forces act on different objects
Balanced forces act on the same object

Action-reaction forces are ALWAYS the same type of force
Balanced forces are NOT always the same types of force

Question 11

Stopping distance has 2 parts to it:

Answer 11

Thinking distance

Braking distance

Question 12

Typical stopping distances

Answer 12

20 mph: 12m(6 thinking, 6 breaking)
30 mph: 23m(9 thinking, 14 breaking)
40 mph: 36m(12 thinking, 24 breaking)
50 mph: 53m(15 thinking, 38 breaking)
60 mph: 73m(18 thinking, 55 breaking)
70 mph: 96m(21 thinking, 75 breaking)

Question 13

Kinetic energy, mass, speed formula

Answer 13

Kinetic energy = 1/2 * mass * (speed)^2