Work, Power and Pressure

Question 1

Mechanical/electrical work done is equal to…

Answer 1

energy transferred

Question 2

What is an equation for mechanical work, related to distance?

Answer 2

W = force x distance

Question 3

What is an equation for mechanical work, related to energy?

Answer 3

W = change in energy (delta E)

Question 4

Define ‘power’ in two ways.

Answer 4

Work done per unit of time
Energy transferred per unit of time

Question 5

What are two equations for power?

Answer 5

P = Work/time
P = delta E/time

Question 6

Define ‘pressure’.

Answer 6

Force per unit area

Question 7

What is the equation for pressure?

Answer 7

P = force/area

Question 8

What happens to pressure of an object underwater as it sinks?

Answer 8

the pressure on it increases, since there are more particles and a bigger weight pushing down on it

Question 9

What happens to pressure of an object as it climbs a mountain?

Answer 9

pressure decreases, less particles
and smaller weight pushing down on it

Question 10

Effect of density of liquid on pressure under liquid surface?

Answer 10

higher the density of liquid, higher pressure on object

Question 11

What is the equation for (change in) pressure under a liquid surface?

Answer 11

Δp = ρgΔh
p = pgh