Ch10 Force and Motion

Question 1

Resultant Force

Answer 1

mass x acceleration

Question 2

Newton’s 2nd law of motion

Answer 2

acceleration is…

1. proportional to resultant force
2. inversely proportional to the mass

Question 3

Weight

Answer 3

mass x GFS

Question 4

Stopping Distance

Answer 4

thinking distance + braking distance

Question 5

Factors affecting Stopping distances

Answer 5

1. Tiredness, alcohol and drugs increase reaction times
2. Poorly maintained vehicles(worn tyres and brakes are less effective)
3. Bad road conditions(have to break with less force so stopping distance is greater)
4. Car mass

Question 6

Thinking distance

Answer 6

speed x reaction time

Question 7

Reaction time

Answer 7

0.2s - 0.9s

Question 8

Momentum

Answer 8

mass x velocity

Question 9

Law of conservation of momentum

Answer 9

Momentum before (M1V1) = momentum after((M1+M2)V3)

Question 10

Force

Answer 10

change in momentum / time

(mv-mu)/t

Question 11

Impact time

Answer 11

If the time is increased, it reduces the force of the impact (F= p/t)
This is why people wear protection in different situations

Question 12

Hooke’s Law

Answer 12

The extension of a spring is directionally proportional to the force applied, as long as it’s limit of proportionality is not exceeded

F = ke

Question 13

EPE

Answer 13

1/2Ke^2

1/2Fe

Question 14

Elastic limit

Answer 14

The furthest point a material can be stretched or deformed while being able to return to its previous shape.

Question 15

Limit of proportionality

Answer 15

The point beyond which Hooke’s law is no longer true when stretching a material

Question 16

inertia

Answer 16

the tendency of an object to move at a constant velocity

Question 17

inertial mass

Answer 17

a measure of the difficulty of changing the object’s velocity

force/acceleration

Question 18

terminal velocity

Answer 18

point at which object moves at a steady speed in a constant direction because the resultant force is 0

Question 19

Large decelerations

Answer 19

overheating

loss of control

Question 20

momentum

Answer 20

mass x velocity

Question 21

conservation of momentum

Answer 21

the total momentum before equals the total momentum after

Question 22

Force

Answer 22

mv-mu/t

change in velocity/ time