# Forces Flashcards Preview

## Year 7 Science Flashcards Ms Lee > Forces > Flashcards

Flashcards in Forces Deck (26)
1
Q

What is a force?

A

A push or a pull

2
Q

What unit are forces measured in?

A

Newton

3
Q

What piece of equipment measured forces?

A

Newton-meter

4
Q

How can forces affect the movement of an object?

A

(i) Change it’s speed (faster/slower)
(ii) Stop it moving
(iii) Change it’s direction
(iv) Change it’s shape

5
Q

How can forces be represented on a diagram?

A

Forces can be represented by arrows in a certain direction.

The size of the force must be labelled.

6
Q

What is a contact force?

A

A contact force is a push or a pull on one object by another object that is touching it.

7
Q

What is a non-contact force?

A

A force that pushes or pulls on an object without touching it is called a non-contact force

8
Q

Give an example of a non-contact force?

A
• Gravitational force
• Magnetic force
• forces due to static electricity
9
Q

Do forces act alone or in pairs?

A

Forces always act in pairs. These pairs are called interaction pairs.

10
Q

What is weight?

A

Theweightof an object is defined as theforceof gravity on the object.

11
Q

What is drag force/air resistance?

A

It is the force that acts on objects as move/fall through the air.

12
Q

How does drag/air resistance affect the speed of a moving object?

A

It slows it down.

13
Q

What type of shape can decrease the effect of air resistance.

A

A stream-lined shape

14
Q

What type of force is thrust?

A

This can be any driving force, it may be a push or pull, but it could be an engine which forces an object forward.

15
Q

What type of force is lift?

A

This is the force required to raise an object through a fluid. e.g. the force pulling an airplane upwards is lift.

16
Q

What is friction?

A

It is a force that acts on objects when they are in contact with a surface, such as the ground. It slows objects down.

17
Q

How can the force of friction be reduced?

A

Lubrication e.g. adding oil to the engine of a car.

18
Q

What is gravity?

A

This pulling force affects every object on Earth. It is a force which pulls everything to the centre of the earth.

19
Q

What is upthrust?

A

This is an upward force which acts in water, it acts on a object against gravity, and is why certain objects float.

20
Q

What is tension?

A

Tension is a pulling force as tension can only pull an object. e.g. there is a tension force on the lead when walking a dog.

21
Q

If the forces on an object are BALANCED (or if there are no forces acting on it), what happens to the object?

A
• a stationary object stays still.

- a moving object continues to move at the same speed and in the same direction.

22
Q

When are forces UNBALANCED?

A

When two forces acting on an object are not equal in size, we say that they are unbalanced forces.

23
Q

When forces are unbalanced it can cause an object to…

A
• Move

- Change it’s speed

24
Q

What is the difference between weight and mass

A
• The weight of an object is the force of gravity on the object. Weight is measured in Newtons.
• Mass is a measurement of how much of something there is. Mass is measured in grams and kilograms.
25
Q

What does Hooke’s Law state?

A

Hooke’s Law states: “If you double the force applied to a spring then the extension of the spring will double”.

26
Q

What is elastic limit

A

This is the point of a spring/elastic beyond which it will deform and not return to it’s original shape.