Forces

Question 1

What are scalar quantities?

Answer 1

Only have magnitude

Question 2

What are vector quantities?

Answer 2

Have magnitude and direction

Question 3

What is a force?

Answer 3

A push or pull on an object caused by an interaction with another object. Forces are vector quantities

Question 4

What are contact forces?

Answer 4

Occur when two objects are touching each other

Question 5

What are non-contact forces?

Answer 5

Act at a distance - gravitational, magnetic, electrostatic

Question 6

What happens when an object exerts a force on another object?

Answer 6

It experiences an equal and opposite force

Question 7

What is a resultant force?

Answer 7

If two or more forces act along the same line
Difference of in opposite directions
Sum if in same direction

Question 8

What happens when the resultant force is 0?

Answer 8

The forces are said to be balanced

Question 9

What is a scale drawing?

Answer 9

Used to find the resultant force when the forces are not acting along the same line
Form a triangle

Question 10

What is a free body diagram?

Answer 10

Shows all the forces acting on a single object
Dota represents object
Arrow direction and size represent direction and magnitude of force

Question 11

How do you calculate weight?

Answer 11

Mass x gravitational field strength

Question 12

What is deformation?

Answer 12

Change in the shape of an object caused by stretching, compressing, twisting or bending

Question 13

What has to happen to cause deformation?

Answer 13

Two or more forces have to act

Question 14

What is elastic deformation?

Answer 14

The object can go back to its original shape and size when the forces are removed

Question 15

What is inelastic deformation?

Answer 15

The object does not go back to its original shape or size when the forces are removed

Question 16

What is the relationship between force and extension?

Answer 16

The extension of an object is directly proportional to the force, as long as the limit of proportionality is not exceeded
Gradient = spring constant

Question 17

What does ke =?

Answer 17

F

Question 18

What is elastic potential energy?

Answer 18

A force that stretches or compresses an object does work on it, causing energy to be transferred to the elastic potential store

Question 19

How is elastic potential energy measured?

Answer 19

Ee = 0.5xkxe^2

Question 20

What are resolving forces?

Answer 20

A single force can always be split into two components at right angles to each other

Question 21

What is a moment?

Answer 21

A force or system of forces can cause an object to rotate. The turning effect of the force is called the moment of the force.
M = Fd
The sum of the clockwise moments equals the sum of the anti clockwise moments when an object is balanced

Question 22

What are levers and gears?

Answer 22

Used to increase the moment of a force, making it easier to lift or rotate an object
If a small gear drives a large gear the moment is increased but the large gear moves slower
A lever allows a large movement of force to be produced by allowing force to be applied further from the pivot

Question 23

What is normal contact force?

Answer 23

Opposite to weight

Question 24

How do you measure weight?

Answer 24

A calibrated spring balance

Question 25

Work done =

Answer 25

Force x distance J or Nm

Question 26

Atmosphere

Answer 26

The atmosphere around the Earth. The atmosphere gets less dense because air molecules colliding with surface area creates atmospheric pressure.

Question 27

Hooke’s Law

Answer 27

The extension of a spring is directly proportional to the force applied, provided that the limit of proportionality is not exceeded.