P8 - Forces

Question 1

What is a scalar quantity?,

Answer 1

Physical quantities that have size/magnitude but NO direction

Question 2

What is a Vector quantity?

Answer 2

Physical quantities that have size/magnitude AND direction

Question 3

Is Velocity and speed the same thing?

Answer 3

No

Question 4

What is speed?

Answer 4

How fast an object is moving

Question 5

What is Velocity?

Answer 5

A speed with a direction

Question 6

What is Velocity? (Simple)

Answer 6

Speed + direction

Question 7

What are examples of Vectors?

Answer 7

Force
Velocity
Momentum

Question 8

What is a force?

Answer 8

A push or pull movement on an object

Question 9

What can a force do to an object?

Answer 9

Change its shape
Change its motion
Change its state of rest (start moving)

Question 10

What is a CONTACT force?

Answer 10

If two objects need to touch to interact

Question 11

What is a NON-CONTACT force?

Answer 11

If they dont need to directly touch to interact

Question 12

What is magnitude?

Answer 12

The size of a quantity

(30 metres)

Question 13

What does the resultant force mean?

Answer 13

The overall force on an object and which direction its going

Question 14

What is the formula linking Work, force and distance?

Answer 14

Work = force x distance

Question 15

What is the formula linking moment, force or distance?

Answer 15

Moment = force x distance

(Nm = F x D)

Question 16

What can fluids be?

Answer 16

A liquid or a gas

Question 17

What is a another word for magnitude?

Answer 17

Size

Question 18

How do you find the centre of mass of a symmetrical onject?

Answer 18

Draw all the lines of symmetry for the object and then find the mid point where they meet.

Question 19

What is another way or saying the centre of mass

Answer 19

The centre of gravity

Question 20

What do you need to find the centre of mass of an irregular shape?

Answer 20

You will need a retort stand, a cork with a pin in it, and a plumb line (string with weight at the bottom)

Question 21

Once you have what you need, How do you find the centre of mass of an irregular object?

Answer 21

Make two holes in the object
Hang it on the cork and pin
Hang the plum line infront of it
Mark the lines
Where the two lines intersect is the centre of gravity

Question 22

What is Newtons second law?

Answer 22

In order to make an object move from rest, the forces must be inbalanced

Question 23

What is Newtons first law (law of motion)?

Answer 23

There needs to be a resultant force to change the motion of an object

Question 24

What does the term ‘no resultant force’ mean?

Answer 24

Motion wont change

Question 25

What is Newtons third law?

Answer 25

When two objects interact with each other, they exert equal and opposite forces on each other

Question 26

What is displacement?

Answer 26

The direction in which the distance is measured (100km in a northern direction)

Question 27

What is the equation for Moment (Nm)?

Answer 27

Moment (Nm) = Force (N) x Distance (m)

Question 28

What is the unit for Force?

Answer 28

Newtons (N)

Question 29

What is the unit for distance?

Answer 29

Metres (m)

Question 30

What is the unit for Moment?

Answer 30

Newton metres (Nm)

Question 31

What is the moment of a force?

Answer 31

The turning effect on an object

Question 32

What does thrust simply mean?

Answer 32

Someones or somethings force

Question 33

What does air resistence (drag) mean?

Answer 33

Thr friction of the air on a moving object

Question 34

If a cars resultant force is 0N and balanced what is its motion like?

Answer 34

If stationary, it wont move If already at constant speed, it will continue (No resultant forces means the motion cant change)

Question 35

What are some examples of Scalar Quantities?

Answer 35

Speed Distance Temperature Time

Question 36

How are vectors represented on a diagram?

Answer 36

By an arrow

Question 37

What does the length of an arrow tell you about a vector?

Answer 37

The magnitude

Question 38

What dies the direction of an arrow tell you about vectors?

Answer 38

The direction of the quantity

Question 39

If two bikes are travelling at the same speed but different directions, are the velocities still the same?

Answer 39

No because they are travelling in different directions

Question 40

Is mass and weight the same thing?

Answer 40

No

Question 41

What does the term 'weight' refer to in physics?

Answer 41

The force acting on an object due to gravity

Question 42

What does the weight of an object depend on?

Answer 42

It depends on the gravitational field strength at the location

Question 43

What is the gravitational field strength of the earth?

Answer 43

9.8N/kg

Question 44

What is the gravitational field strength of the moon?

Answer 44

1.6N/kg

Question 45

What does 1kg mass weigh less on the moon than it does on earth?

Answer 45

The gravitational field strength on the surface of the moon is less

Question 46

How do you calculate the weight of an object?

Answer 46

Weight = Mass x gravitational field strength

Question 47

Describe the relationship between mass and weight?

Answer 47

They are directly proportional to each other

Question 48

What do levers make it easier for us to do work?

Answer 48

Levers increase the distance from the pivot at which the force is applied. This means less force is needed to get the same moment

Question 49

What formula describes Newtons 2nd Law about Resultant force?

Answer 49

Resultant force = mass x acceleration