Forces

Question 1

What is a scalar

Answer 1

Just a number with no direction

Question 2

What is a vector

Answer 2

A number and a direction

Question 3

Give 3 examples of a scalar

Answer 3

Distance, temperature , speed

Question 4

Give 3 examples of a vector

Answer 4

Displacement,
Weight,
Velocity

Question 5

What is a force?

Answer 5

Can cause an object to change its velocity

Question 6

What are the 2 categories forces can be split into

Answer 6

Contact and Non-contact

Question 7

Give 3 examples of contact forces

Answer 7

Friction
Air- resistance
Tension

Question 8

Give 3 examples of non-contact forces

Answer 8

Gravitational forces
Electrostatic forces
Magnetic forces

Question 9

Is force a vector or a scalar?

Answer 9

Vector

Question 10

What is weight?

Answer 10

The force that acts on an object due to gravity and the object’s mass.

Question 11

Formula for weight

Answer 11

Weight (N) = Mass (kg) x gravity (N/kg)

Question 12

What does weight depend on?

Answer 12

Gravity, changes on different planets

Question 13

What is the unit used for weight

Answer 13

Newtons (N)

Question 14

What is the unit for gravitational field strength?

Answer 14

N/kg

Question 15

What is meant by an objects centre of mass?

Answer 15

The single point where an objects weight can be considered to act through

Question 16

What equipment can be used to measure an objects weight?

Answer 16

Newton-meter

Question 17

What is the name given to the single force that is equivalent to all the other forces acting on a given object?

Answer 17

Resultant force

Question 18

What is the equation to calculate work done?

Answer 18

Work done = Force x distance

Question 19

Under what circumstance is 1 Joule of work done?

Answer 19

When a force of 1 Newton causes a displacement of 1 metre.

Question 20

How many Newton metres are equal to 1 joule of energy?

Answer 20

1J = 1 Nm

Question 21

What occurs when work is done against frictional forces?

Answer 21

A rise in temperature of the object
Kinetic energy converted to heat

Question 22

Why does air resistance slow down a projectile?

Answer 22

kinetic energy converted to heat, slowing object down
object does work against the resistance

Question 23

Explain the relationship between the force applied and the extension of an elastic object

Answer 23

Extension is directly proportional to force applied

Question 24

What is meant by an inelastic deformation?

Answer 24

The object doesn’t return to its original shape after force is removed
Object is permanently stretched

Question 25

State the equation linking force, spring constant and extension.

Answer 25

Force (N) = Spring constant (N/m) x extension (m)

Question 26

What type if energy is stored in a stretched spring?

Answer 26

Elastic potential energy

Question 27

Extension can be replaced with ________ in the equation for spring force.

Answer 27

Compression

Question 28

What happens when an object reaches the limit of proportionality when being stretched?

Answer 28

The extension doesn’t increase anymore and can snap, before , as you increase force, the extension also increases.

Question 29

Define Hooke’s Law.

Answer 29

If you apply force to a spring, then the force stretches the spring.

Question 30

Unbalanced forces = ______ effect

Answer 30

Turning effect

Question 31

Equation for acceleration

Answer 31

Acceleration = Velocity / Time

Question 32

What is Inertia

Answer 32

An object in motion or at rest will stay in motion or at rest unless acted upon by an outside force.

Question 33

State Newtons third law

Answer 33

For every action there is an equal and opposite reaction.

Question 34

Equation for force

Answer 34

Force = Mass x Acceleration

Question 35

Equation for momentum

Answer 35

Momentum ( kg m/s) = Mass (kg) x Velocity (m/s)

Question 36

State the law of conservation of momentum

Answer 36

Momentum is always conserved Moment before = Momentum afterwards

Question 37

Force =

Answer 37

Mass x Change in velocity / Change in time

Question 38

State an equation linking momentum, force and time.

Answer 38

Force x time = change in momentum

Question 39

Explain how a seatbelt improves a passengers safety during a collision.

Answer 39

Increases time taken for body’s momentum to reach zero

Question 40

Stopping distance = ______ distance + ______ distance

Answer 40

Thinking; braking