P5: Forces (triple)

Question 1

What is a vector?

Answer 1

A quantity with magnitude and direction.

Question 2

What is a scalar quantity?

Answer 2

A quantity with magnitude.

Question 3

What is a contact force?

Answer 3

When two objects have to be touching for a force to act.

Question 4

What is a non-contact force?

Answer 4

When the objects don’t need to be touching for the force to act.

Question 5

What is mass?

Answer 5

The amount of the object

It doesn’t change ever

Question 6

What is weight?

Answer 6

The force acting on an object due to gravity.

Question 7

What is the centre of mass of an object?

Answer 7

Where the force (weight) is pulling down on the object. It is usually the centre.

Question 8

What is a free body diagram?

Answer 8

It describes all the forces acting on an isolated object describing the forces as arrows. The longer the arrow the greater the force.

Question 9

What is the resultant force on an object?

Answer 9

The overall force acting on an object.

Question 10

When is an object in equilibrium?

Answer 10

When the forces on it are balanced.

Question 11

What is meant by an object that can be elastically deformed?

Answer 11

It goes back to its original shape after a force has been removed.

Question 12

What is meant by an object being inelastically deformed?

Answer 12

When an object doesn’t return back to its original size a force has been removed.

Question 13

What is the typical speed of a person walking?

Answer 13

1.5 m/s

Question 14

What is the typical speed of a person running?

Answer 14

3 m/s

Question 15

What is the typical speed of a person cycling?

Answer 15

6 m/s

Question 16

What is the typical speed of a car?

Answer 16

25 m/s

Question 17

What is the typical speed of a train?

Answer 17

30 m/s

Question 18

What is the typical speed of a plane?

Answer 18

250 m/s

Question 19

How do you find the distance travelled using a velocity-time graph?

Answer 19

The area under the graph.

Question 20

How is acceleration shown on a free body diagram?

Answer 20

On arrow is bigger than the other.

Question 21

What is inertia?

Answer 21

The tendency for motion to remain unchanged.

Question 22

Stopping distance =

Answer 22

Thinking distance + braking distance

Question 23

What is thinking distance effected by?

Answer 23

Speed

Reaction time

Question 24

What is braking distance affected by?

Answer 24

Speed
Weather/road surface
Condition of tyre
Quality of brakes

Question 25

Moment =

Answer 25

Force * distance

Question 26

What is a moment?

Answer 26

The turning effect of a force.

Question 27

What are the functions of gears?

Answer 27

to transmit rotational effects

Question 28

why does the pressure of liquids increase as the depth increases?

Answer 28

the weight of the greater number of particles above a point pushes down on the point increasing the pressure

Question 29

What is upthrust?

Answer 29

the force exerted onto the bottom of an object when submerged in a fluid due to the fluid's pressure

Question 30

How does upthrust have an upwards resultant force?

Answer 30

the pressure of a fluid increases with depth so more force is exerted on the bottom of the object creating an upthrust

Question 31

What happens to an object in a fluid that has an equal weight being displaced and upthrust?

Answer 31

it will float

Question 32

What is air resistance?

Answer 32

the frictional force produced by air acting ona moving objects.