Module 3

Question 1

How is instantanous speed found from a distance time graph

Answer 1

Finding gradient of tangent

Question 2

Define acceleration

Answer 2

Rate of change opf velocity dv/dt

Question 3

How to determine acceleration from a velocity time graph

Answer 3

Gradient

Question 4

How to determine displacement from velocity time graph

Answer 4

Area underneath (sometimes by counting squares)

Question 5

How to calculate stopping distance

Answer 5

Thinking distance - Braking distance

Question 6

How to calculate thinking distance

Answer 6

Speed x reaction time

Question 7

3 methods that can be used to accurately determine g

Answer 7

Electromagmet and trapdoor
Lightgates
Taking pictures

Question 8

Equation linking mass and weight

Answer 8

W=mg

Question 9

What can be used ton determine the centre of gravity fro 2D objects

Answer 9

Plum line
(weight on a string - when it comes to rest at the centre of gravity)

Question 10

Define terminal velocity

Answer 10

When the drag force of the object is equal and opposite to its weight

Question 11

Define moment

Answer 11

Force x perpendicular distance
moment = fx

Question 12

What is the principle of moments

Answer 12

For a body in roational equalibrium, the sum of the anticlockwise moments about a point is equal to the sum of the cockwise moents about the same point

Question 13

Define couple

Answer 13

A pair of equal and opposite forces that bare parralel along different lines

Question 14

Define torque

Answer 14

Moment of a couple

Question 15

How to calculate torque

Answer 15

One of the forces x perpendicular seperation between forces
Torque = fd

Question 16

Equation for upthrust

Answer 16

Uprthrust = Axpg

Question 17

State Archemedes principle

Answer 17

The upthrust exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces.

Question 18

Equation for work done

Answer 18

Force x distance (in direction of foce)

Question 19

State the principle of conservation of energy

Answer 19

The total energy in a closed system remains constant: energy can never be created or destroyed only transferred from on form to another

Question 20

Equation for GPE

Answer 20

GPE = mgh

Question 21

Define elastic deformation

Answer 21

The spring will retern to its origional length once the force is removed

Question 22

Define plastic deformation

Answer 22

Permanent structural chanes to the spring occur and it does not return to its origional length when the force is removed

Question 23

State hookes law

Answer 23

The extension of the spring is directly proportional to the force applied as long as the elastic limit of the spring is not exceeded.

Question 24

What is k in f=kx

Answer 24

Force constant of the spring

Question 25

Define brittle

Answer 25

Elastic behaviour up to breaking point

Question 26

Define ductile

Answer 26

Elastic and plastic regions before the material breaks

Question 27

Newtons 1st law

Answer 27

An object will remain at rest or continue to move with constant velocity unless acted upon by a resultant force

Question 28

Newtons 3rd law

Answer 28

If a body A exerts a force on body B then body B exerts and equal and opposite force on body A

Question 29

Law of conservation of momentum

Answer 29

For a system of interacting objects, the total momentum in a specified direction remains constant, as long as no external forces act on the system

Question 30

What is conserved in an elastic collision

Answer 30

Kinetic energy

Question 31

Newtons 2nd law

Answer 31

The net force acting on an object is directly proportional to the rate of change of its momentum and is in the same direction

Question 32

Equation for newtons 2nd law

Answer 32

F=dp/dt Rate of change of momentum

Question 33

Define impulse

Answer 33

Change in momentum (Fxt)