Forces, energy and power

Question 1

What is friction?

Answer 1

Force which opposes the motion of an object. Acts between two surface in contact

Question 2

How to increase friction?

Answer 2

Increase surface area
Increase the roughness of surface

Question 3

How to decrease friction?

Answer 3

Lubricant eg oil
Thin layer of air

Question 4

What is air resistance?

Answer 4

type of friction force due to air particles coming into contact with an object

Question 5

If forces act in same direction?

Answer 5

Add together

Question 6

Newton first law?

Answer 6

An object will remain at rest or move at a constant speed in a straight line unless acted upon by an unbalanced force

Question 7

Newton Second Law>

Answer 7

F=ma

Question 8

Newtons Third Law?

Answer 8

for every action there is an equal and opposite reaction

Question 9

What is tension?

Answer 9

the pulling force of a string or rope

Question 10

What is free fall?

Answer 10

object experience only force due to gravity acting in on it

Question 11

What is terminal velocity?

Answer 11

air resistance and weight downwards are equal

Question 12

What is reaction force?

Answer 12

the upward force due to the scales = reading on the scales

Question 13

Lift is stationary or constant speed?

Answer 13

R=E balanced forces

Question 14

Accelerating upwards or decelerating downwards?

Answer 14

F=ma=R-W
Increase in weight

Question 15

Accelerating downwards or Decelerating upwards?

Answer 15

F=ma+W-R
Decrease in weight

Question 16

As angle to the horizontal increases?

Answer 16

Vertiacl component increases and horizontal decrease