9I — Forces And Motion

Question 1

1) What are the units for speed?

2) What is the formula for speed?

Answer 1

1) The units for speed are km/h, m/s, or mph.

2) Speed = Distance/Time

Question 2

1) What is a mean(average) speed?

2) What is the relative speed?

Answer 2

1) The total distance something travels divided by the total time taken is the mean (or average) speed for a journey.
2) The speed of one object compared to another – both objects could be moving.

Question 3

What is a distance-time graph?

Answer 3

A graph that shows how far and how fast something travels during a journey. Steeper lines on the graph show faster speeds.

Question 4

1) What is the gradient?

2) How do you calculate the gradient?

Answer 4

1) The gradient of a line on a graph is a measure of how steep the line is.
2) gradient = vertical change(distance moved)/ horizontal change (time taken)

Question 5

1) What is a force multiplier?

2) What is a distance multiplier?

Answer 5

1) Force multipliers are when the force that is put in (the effort) is increased.
2) A distance multipliers is if a machine makes the load move further than the effort.

Question 6

What is a turning force called?

Answer 6

A turning force is called a moment.

Question 7

1) What is the formula for moment?

2) How is the moment increased?

Answer 7

1) moment (in N m) = force (in N) × perpendicular distance from the pivot (m)
2) The longer the distance of the lever, the greater the moment.

Question 8

List examples of simple machines

Answer 8

— Lever
— Ramp
— Pulley

Question 9

1) What is work done and what is the unit for work?

2) What is the formula for work?

Answer 9

1) The energy transferred when a force moves an object. It is measured in joules(J).
2) work = force × distance moved in the direction of the force

Question 10

Define Equilibrium

Answer 10

Equilibrium means in balance