Paper 1- Mechanics

Question 1

What effect do forces at 90 degrees have on each each other?

Answer 1

No effect

Question 2

State the principle of moments

Answer 2

In equilibrium, the total clockwise moment about a point is equal to the total clockwise moment about the same point

Question 3

Define a moment

Answer 3

The force multiplied by the perpendicular distance between the pivot and line of action of the force

Question 4

What 2 conditions must be satisfied for a body to be in equilibrium?

Answer 4

The resultant force must be 0
The principle of moments must be satisfied

Question 5

What is a couple?

Answer 5

A pair of equal and opposite coplanar forces acting on a body along different parallel lines of action

Question 6

The moment of a couple=…?

Answer 6

Force x perpendicular distance between their lines of action

Question 7

Define centre of mass

Answer 7

The point at which all of the mass of a body can be thought to act on

Question 8

What is the gradient of a displacement-time graph equal to?

Answer 8

The object’s velocity

Question 9

What is the gradient of a velocity-time graph equal to?

Answer 9

The object’s acceleration

Question 10

What is the area under a velocity-time graph equal to?

Answer 10

The distance the object has travelled

Question 11

What is Newton’s first law?

Answer 11

If a body s at rest it remains at rest, or if it is moving it travels at a constant velocity unless acted on by a resultant external force

Question 12

What is Newton’s second law?

Answer 12

The rate of change of momentum of a body is proportional to the applied force and occurs in the same direction

Question 13

What is Newton’s third law?

Answer 13

If body A exerts a force on body B, body B exerts an equal but oppositely directed force on body A

Question 14

Is momentum scalar or vector?

Answer 14

Vector

Question 15

What is momentum a measure of?

Answer 15

How difficult it is to stop an object moving

Question 16

State the principle of conservation of momentum

Answer 16

In any collision or explosion, the total momentum of the system remains constant provided no external forces act

Question 17

What is an elastic collision?

Answer 17

A collision in which kinetic energy and momentum are both conserves

Question 18

What is an inelastic collision?

Answer 18

A collision in which only momentum is conserved

Question 19

Do perfectly elastic collisions exist in reality and why/ why not?

Answer 19

No
There will always be an energy transfer to heat/ sound/ deformation of colliding bodies

Question 20

Define energy

Answer 20

That which enables a body to do work

Question 21

State the conservation of energy

Answer 21

Energy can’t be created or destroyed, it can only be transformed from one form to another

Question 22

Define power

Answer 22

The rate at which work is done

Question 23

Define impulse

Answer 23

The product of a force acting on an object and the time for which it acts

Question 24

What is the area under a force-time graph equal to?

Answer 24

Impulse

Question 25

What effect does increasing the collision time have on the force?

Answer 25

Force decreases

Question 26

What type of collision is an explosion?

Answer 26

Inelastic

Question 27

What type of collision is one in which the objects stick together after the collision?

Answer 27

Inelastic

Question 28

Define power

Answer 28

The rate at which work is done

Question 29

Define the Watt as a unit

Answer 29

1 Joule transferred per second

Question 30

Define work done

Answer 30

A force causing motion multiplied by the distance travelled in the direction of the force

Question 31

Define efficiency

Answer 31

A measure of how efficiently a system transfers energy

Question 32

What is the area under a force-displacement graph equal to?

Answer 32

Work done