Topic 5 - Forces (paper 2)

Question 1

What is a moment?

Answer 1

rotational or turning effect of a force

Question 2

What is the formula for a “moment”?

Answer 2

M = Fd

Question 3

What is the unit for a “moment”

Answer 3

Newton metres (Nm)

Question 4

What is the “d” in the equation for “moments”

Answer 4

perpendicular distance

Question 5

In a balanced seesaw the total clockwise moment is …….. to the total anti- clockwise moment. Fill in the gap.

Answer 5

Equal to

Question 6

How do levers work?

Answer 6

They work by transmitting the turning effect of a force

Question 7

What is the formula for weight?

Answer 7

Weight = mass x gravitational field strength
W = mg

Question 8

When two gears are connected, do the gears turn in opposite directions, or the same directions?

Answer 8

Opposite directions

Question 9

What is the relationship between the ratio of the turning effect of the two gears to the ratio of the radius of the two gears

Answer 9

They are proportional

Question 9

True or False? All states exert pressure.

Answer 9

True

Question 10

What states does the term “fluid” refer to?

Answer 10

Liquid or Gas

Question 11

What is the formula for pressure?

Answer 11

Pressure = force/ area
P = F/A

Question 12

What’s the unit for pressure?

Answer 12

Pascals (Pa)

Question 13

What are the factors which determined the pressure exerted by a liquid?

Answer 13

The depth, density of liquid, gravitational field strength

Question 14

What is the formula for pressure in a liquid?

Answer 14

p = hpg

Question 15

What’s the units of pressure in a liquid?

Answer 15

Pascals (Pa)

Question 16

What It is upthrust caused by?

Answer 16

The pressure on the bottom of the object being greater than the pressure on the top of the object

Question 17

What will happen to an object if it is more dense than the liquid its in?

Answer 17

It will sink

Question 18

Is atmospheric pressure higher or lower at a higher elevation?

Answer 18

Lower

Question 19

What does atmospheric pressure refer to

Answer 19

the total force of all the air particles constantly colliding with everything, from all sides

Question 20

Why is there a greater atmospheric pressure at sea level than at a higher elevation?

Answer 20

There are more gas particles at sea level to collide with objects and the air is more dense at sea level

Question 21

What are the two main gases which make up the atmosphere?

Answer 21

Nitrogen and Oxygen

Question 22

What is a scalar quantity?

Answer 22

Only has magnitude

Question 23

What is a vector quantity?

Answer 23

Has both direction and magnitude

Question 24

Is speed a scalar or vector quantity?

Answer 24

Scalar quantity

Question 25

Is velocity a scalar or vector quantity?

Answer 25

Vector quantity

Question 26

Is distance a scalar or vector quantity?

Answer 26

Vector quantity

Question 27

Is displacement a scalar or vector quantity?

Answer 27

Scalar quantity

Question 28

What is the formula for velocity?

Answer 28

velocity = speed/ time v = s/t

Question 29

What is acceleration?

Answer 29

The rate of change of velocity

Question 30

What is the formula for acceleration?

Answer 30

acceleration = change in velocity/ time

Question 31

What is another formula for acceleration?

Answer 31

v^2 - u^2 = 2as final velocity^2 - initial velocity^2 = 2 x acceleration x distance

Question 32

On a distance/ time graph what axis is distance on?

Answer 32

y-axis

Question 33

On a distance/ time graph what axis is time on?

Answer 33

x-axis

Question 34

What does the gradient of a distance/time graph tell us?

Answer 34

the speed of the object

Question 35

What does a flat line on a distance/time graph tell us?

Answer 35

The object is stationary

Question 36

How to find the velocity at a point on a distance/time graph?

Answer 36

Draw a tangent at the point and use it to find the gradient of the line

Question 37

On a velocityy/ time graph what axis is velocity on?

Answer 37

y-axis

Question 38

On a velocity/ time graph what axis is time on?

Answer 38

x-axis

Question 39

What does a flat line on a velocity/time graph tell us?

Answer 39

The object is moving at a constant velocity

Question 40

What does the gradient of a velocity/time graph tell us?

Answer 40

The acceleration or deceleration of the object?

Question 41

How can you tell the distance traveled on a velocity/time graph?

Answer 41

The area under the curve

Question 42

What is the force that causes an object to fall towards the earth?

Answer 42

Weight

Question 43

What is the size of the air resistance dependent on?

Answer 43

surface area and velocity

Question 44

As the velocity of a falling object increases, the air resistance....... Fill in the gap.

Answer 44

Increases

Question 45

What is "terminal velocity"

Answer 45

When an object is falling with a constant velocity

Question 46

When is terminal velocity reached?

Answer 46

The resultant force is zero and the weight has the same magnitude as the air resistance