Year 1 refresher

Question 1

Define friction

Answer 1

Force that arises whenever the body moves, or tends to move across another surface
Coefficient x reaction force

Question 2

Limiting friction

Answer 2

A limit to the frictional force with which movement between 2 surfaces can be resisted
efficient of limiting friction x perpendicular reaction

Question 3

What does the coefficient depend on?

Answer 3

Material roughness

Question 4

Sliding friction

Answer 4

the frictional force between 2 surfaces when there is movement

Question 5

Rolling friction

Answer 5

influenced by weight, radius, surface deformability

Question 6

Is it easier to push or pull a desk

Answer 6

Easier to pull than push as the weight component is reducing the normal reaction force

Question 7

Torque

Answer 7

the turning effect produced by a force

force x perpendicular distance from acid of rotation

Question 8

angular velocity

Answer 8

change in angular displacement/ change in time

Question 9

angular speed

Answer 9

change in angular distance/change in time

Question 10

newtons laws

Answer 10

1) intertia
2) force = mass x acceleration
3) action reaction

Question 11

Elasticity

Answer 11

ability to return to original shape

Question 12

Stability

Answer 12

lower the centre of gravity, large base of support

Question 13

is velocity a vector a scalar value

Answer 13

vector (magnitude and direction)

Question 14

is distance a vector or scalar value

Answer 14

scalar (just direction)