Forces (5) - Pt1

Question 1

What are vectors?

Answer 1

Vector quantities have magnitude and direction

Question 2

Give examples of 5 vector quantities

Answer 2

Dates are mostly for Vigins
Displacement
Acceleration 
Momentum 
Force
Velocity

Question 3

What are scalar quantities?

Answer 3

Only have magnitude no direction

Question 4

Give 5 examples of scalar quantities

Answer 4

MighTy STanD
Mass
Temperature 
Speed
Time
Distance

Question 5

What’s a force?

Answer 5

It’s a push or pull on an object that’s caused by it interacting with something
All forces are contract or non-contract

Question 6

What’s a contact force and give 4 examples?

Answer 6

When 2 objects have to be touching for the force to act

Friction, air resistance, tension and normal contact force.

Question 7

What a non-contact force and give 3 examples?

Answer 7

Objects that don’t need to be touching for the force to act
Magnetic force
Gravitational force
Electrostatic force

Question 8

What’s an interaction pair?

Answer 8

Forces that are equal and opposite that act on 2 interacting objects

Question 9

What 2 effects does gravity have?

Answer 9

• gives everything weight

- on the surface if a planter it makes everything fall to the ground

Question 10

What’s weight?

Answer 10

• Weight is the force acting on an object due to gravity.
• The force of gravity close to the Earth is due to the gravitational field around the Earth.
• The weight of an object depends on the gravitational field strength at the point where the object is.

Question 11

What’s the formula to find weight?

Answer 11

Weight (N) = Mass (kg) x gravitational field strength (N/Kg)

W = Mg

Question 12

What’s the relationship between mass and weight?

Answer 12

They’re directly proportional

Question 13

What’s the approximate gravitational field strength for earth?

Answer 13

9.8 N/Kg

Question 14

What’s the centre of mass of an object?

Answer 14

• A point where you can assume the whole mass is concentrated
• where the weight of an object may be considered to act at a single point

Question 15

Is mass a force?

Answer 15

No

Question 16

What in weight measured with?

Answer 16

using a calibrated spring-balance (a newton meter)

Question 17

What’s a resultant force?

Answer 17

If you had a number of forces acting on a single point they can be replaced by a single force (resultant force)

Question 18

What’s the formula to find work done?

Answer 18

Work done (J) = Force (N) x Distance (m)
W=Fs

Question 19

Explain the equation W=Fs

Answer 19

• a force causes an object to move a certain distance
• so work is done on the object.
• So a force does work on an object when the force causes a displacement of the object.

Question 20

What’s the conversion of joules to newton meters?

Answer 20

1J = 1Nm

Question 21

In terms of forces and energy what happens when you push something along a rough surface?

Answer 21

• you’re doing work against frictional forces
• energy is transferred to kinetic energy stores as the object moves
• but some is also transferred to thermal energy stores due to friction
• causing the overall temperature to increase

Question 22

What does it mean if an object is at equilibrium?

Answer 22

If All of the forces acting on the object combine to give a resultant of zero then the object is at equilibrium

Question 23

What does it mean if an object is elastically deformed?

Answer 23

It can go back to its original shape and length once the force has been removed.
These objects are called elastic objects

Question 24

What does it mean if an object is inelastically deformed?

Answer 24

If It doesn’t return to its original shape or length after the force has been removed

Question 25

When you Appleby a force to an object what 3 things can happen to it?

Answer 25

You may cause it to: stretch, compress or bend

Question 26

Why do you need more then one force on a stationary object to compress, stretch or bend it?

Answer 26

Otherwise the object would simply move in the direction of the applied force, instead of changing shape

Question 27

It terms of energy stores what happens to an object when it’s stretched or compressed?

Answer 27

• work is done causing energy to be transferred to the elastic potential energy stores of the object
• if it’s elastically deformed all the energy is transferred to the objects potential energy stores

Question 28

What’s the relationship between the force on a stretched spring and the extension stretched spring?

Answer 28

Directly proportional

Question 29

What’s the equation for finding the force applied to a spring?

Answer 29

Force (N) = spring constant (N/m) x Extension (m)

F=Ke

Question 30

How would you change F=Ke for an object being compressed?

Answer 30

e becomes the difference between the lengths of the neutral spring and the compressed spring