Chapter 5 - Forces

Question 1

What do vector quantities have

Answer 1

Vector quantities have a magnitude and direction

Question 2

What do you call a physical quantity that only has magnitude and no direction

Answer 2

Scalar quantities

Question 3

What are examples of vector quantities

Answer 3

Force
Velocity
Displacement
Acceleration
Momentum

Question 4

What are examples of scalar quantities

Answer 4

Speed
Distance
Mask
Temperature
Time

Question 5

What are vectors usually represented by

Answer 5

An arrow
The length of the arrow shows the magnitude
The direction of the arrow shows the direction of the quantity

Question 6

All forces are either …

Answer 6

Contact on noncontact

Question 7

What is a contact force

Answer 7

When two objects have to be touching for a force to act, that forces called a contact force

E.g. friction, air resistance

Question 8

What is a noncontact force

Answer 8

If the objects do not need to be touching for the force to act, the force is a noncontact force

E.g. magnetic force

Question 9

What is gravitational force

Answer 9

Gravitational forces the force of attraction between masses

Question 10

What gives everything a weight

Answer 10

Gravity

Question 11

What is the difference between weight and mass

Answer 11

Mass is just the amount of stuff in an object. The mass of an object will have the same value anywhere in the universe

Weight is the force acting on an object due to gravity (the pull of the gravitational force on the object). This can be different on different planets

Question 12

What does the weight of an object depend upon

Answer 12

I depend on the strength of the gravitational field at the location of the object

Question 13

What is weight measured in

Answer 13

Newtons

Question 14

What do you measure weight with?

Answer 14

Newton metre

Question 15

Are mass and weight directly proportional

Answer 15

Yes they are

Question 16

How do you calculate the weight of an object if you know it’s mass and the Strength of the gravitational field

Answer 16

Weight = mass X gravitational field strength

Question 17

How do you show all the forces acting on an object

Answer 17

Free body diagrams

Question 18

What is a resultant force

Answer 18

The resultant force is the overall force on a point or object

Question 19

What is an example of resultant force on the skydiver

Answer 19

Skydiver has more than one force acting at a single point so you can replace them with a single force which is called the resultant force. If the forces all act along the same line the overall effect is found by adding those going in the same direction and subtracting any going in the opposite direction

Question 20

What must be done to make something move

Answer 20

A force must be applied

Question 21

What does the thing applying the force need to move something

Answer 21

The thing applying the force needs a source of energy e.g. fuel or food

The force does work to move the object and the energy is transferred from one store to another

Question 22

How do you work out how much work has been done if you’re given the force and distance moved along the line of action of the force

Answer 22

Work done = force X distance

Question 23

When is one joule of work done

Answer 23

One jewel of work is done when a force of one Newton causes an object move a distance of 1 m

1J = 1NM