Year 1 Mechanics

Question 1

when is an object at equilibrium?

Answer 1

When a = 0

Question 2

suvat equation with v, u, a, t

Answer 2

v = u + at

Question 3

suvat equation with s, u, v, t

Answer 3

s = ((u+v)/2) x t

Question 4

suvat equation with s, v, a, t

Answer 4

s = vt - ((a x t^2)/2)

Question 5

suvat equation with v, u, a, s

Answer 5

v^2 = u^2 + 2 x a x s

Question 6

suvat equation with s, u, t, a

Answer 6

s = ut + ((a x t^2)/2)

Question 7

f =

Answer 7

ma

Question 8

w =

Answer 8

mg

Question 9

If two connected particles are moving in the same straight line what can you do?

Answer 9

Treat them as one particle

Question 10

Newtons third law

Answer 10

For every action there is an equal and opposite reaction

Question 11

What is the assumption for the following model?

Particle

Answer 11

Mass of the object is concentrated at a single point

Rotational forces and air resistance can be ignored

Question 12

What is the assumption for the following model?

Rod

Answer 12

Mass is concentrated along a line
No thickness
rigid

Question 13

What is the assumption for the following model?

Lamina

Answer 13

Mass is distributed across a flat surface

Question 14

What is the assumption for the following model?

Uniform body

Answer 14

Mass of the object is concentrated at a single point at the geometrical centre of the body - the centre of mass

Question 15

What is the assumption for the following model?

Light object

Answer 15

Treat object as having 0 mass

tension the same at both ends of a light string

Question 16

What is the assumption for the following model?

Inextensible string

Answer 16

Acceleration is the same in objects connected by a taught inextensible string

Question 17

What is the assumption for the following model?

Smooth surface

Answer 17

Assume that there is no friction between the surface and any object on it

Question 18

What is the assumption for the following model?

Rough surface

Answer 18

Objects in contact with the surface experience a frictional force if they are moving or are acted on by a force

Question 19

What is the assumption for the following model?

Wire

Answer 19

treated as one dimensional

Question 20

What is the assumption for the following model?

Smooth and light pulley

Answer 20

Pulley has no mass

Tension is the same on either side of the pulley

Question 21

What is the assumption for the following model?

Bead

Answer 21

Moves freely along a wire or string

Tension is the same on either side of the bead

Question 22

What is the assumption for the following model?

Peg

Answer 22

Dimensionless and fixed

Can be rough or smooth as specified in question

Question 23

What is the assumption for the following model?

Air resistance

Answer 23

Usually modelled as being negligible

Question 24

What is the assumption for the following model?

Gravity

Answer 24

Assume that all objects with mass are attracted towards the Earth
Earth’s gravity is uniform and acts vertically downwards
g is constant and is taken as 9.8ms-2 unless otherwise stated in the question