Mechanics year 11

Question 1

Whats the formula for friction?

Answer 1

Question 2

what is the stress formula

Answer 2

Question 3

What are the main materials on a stress strain diagram?

Answer 3

• Ductile (copper)
• brittle (cast iron or glass)
• plastic
• strong non brittle material (mild steel)

Question 4

Find the strain of a brake rod if it is

• compressed O.3mm
• when it is 70mm long?

Answer 4

Question 5

What is the strain formula?

Answer 5

ε=e/L

ε=stress

e= extension

L=original length

Question 6

What is the angle of repose formula and what does it tell you?

Answer 6

μ=tanθ

Where the μ is the coefficent of friction and the θ is the angle of the slope where an object is at the point of sliding

Question 7

What are the forces acting on this object?

Answer 7

The forces acting on this object in the horzontal are: the pull force in the direction the object is moving ifit overcomes friction and the friction force in the opposite direction.

the forces acting on this obect in the vertical are: the weight force of gravity x objects weight and the reaction force which is the ground over coming the force of gravity to hold the object up.

Question 8

What is the pascal’s principle?

Answer 8

Its the pressure applied to an enclosed liquid in transmitting undiminished to every point in the fluid and to the walls of the container

Question 9

What is the pascal’s principle formula?

Answer 9

Question 10

Explain what does a first order lever look like

Answer 10

A First Order lever has effort acting on one side of the fulcrum whilst it has load acting on the other side. Like a seesaw.

Question 11

Billy was here

So is harry

Nick was here as well

Answer 11

Brad 看起来似乎不怎么聪明

Question 12

Efficiency in Levers

Question 13

What is Velocity Ratio?

Answer 13

Velocity ratio is Length of Effort Over Length of Load moved. It does not have a unit because it cancelled out.