Equations

Question 1

What is the equation for kinetic energy?

Answer 1

E = ½ * m * v^2

E = kinetic energy - J (joules)
m = mass - kg (kilograms)
v = speed - m/s (meters per second)

Question 2

What is the equation for gravitational potential energy?

Answer 2

E = mgh

E = gravitational potential energy - J (joules)
m = mass - kg (kilograms)
g = gravitational field strength - N/kg (newton’s per kilogram)
h = height - m (meters)

Question 3

What is the equation for elastic potential energy?

Answer 3

Ee = ½ * k * e^2

Ee = elastic potential energy - J (joules)
k = spring constant - N/m (newton’s per meter)
e = extension - m (meters)

Question 4

What is the equation for specific heat capacity?

Answer 4

ΔE = m * c * Δθ

ΔE = change in thermal energy - J (joules)
m = mass - kg (kilograms)
c = specific heat capacity - J/kg˚C (joules per kilogram per degree Celsius)
Δθ = temperature change - ˚C (degree Celsius)

Question 5

What is the equation for power, using energy transfered?

Answer 5

P = E / t

P = power - W (watts)
E = energy transferred - J (joules)
t = time - s (seconds)

Question 6

What is the equation for power, using work done?

Answer 6

P = W / t

P = power - W (watts)
W = work done - J (joules)
t = time - s (seconds)

Question 7

What are the equations for efficiency?

Answer 7

efficiency = useful energy out / total energy in

efficiency = useful power out / total power in

Question 8

What is the equation for calculating charge?

Answer 8

Q = I * t

Q = Charge - C (coulombs)
I = Current - A (amps)
t = Time - s (seconds)

Question 9

What is the equation for calculating potential difference?

Answer 9

V = I * R

V = Potential difference - V (volts)
I = Current - A (amps)
R = Resistance - Ω (ohms)

Question 10

What is the equation for calculating power from potential difference?

Answer 10

P = V * I

P = Power - W (watts)
V = Potential difference - V (volts)
I = Current - A (amps)

Question 11

What is the equation for calculating power from resistance?

Answer 11

P = I^2 * R

P = Power - W (watts)
I = Current - A (amps)
R = Resistance - Ω (ohms)

Question 12

What is the equation for power and energy transfer?

Answer 12

E = P * t

E = Energy - J (joules)
P = Power - W (watts)
t = Time - s (seconds)

Question 13

what is the equation for calculating energy transfered from charge and potential difference?

Answer 13

E = Q * V

E = Energy - J (joules)
Q = Charge - C (coulombs)
V = Potential difference - V (volts)

Question 14

What is the equation for calculating weight?

Answer 14

W = m * g

W = weight - N (newton’s)
m = mass - kg (kilograms)
g = gravitational field
strength - N/kg (newton’s per
kilogram)

Question 15

What is the equation for calculating weight?

Answer 15

W = F * s

W = work done - J (joules)
F = force - N (newton’s)
s = distance - m (meters)

Question 16

What is the equation for calculating the force needed to stretch an object?

Answer 16

F = k * e

F = force - N (newtons)
k = spring constant - N/m (newtons per meter)
e = extension - m (meters)

Question 17

What is the equation for calculating the moment effect of force?

Answer 17

M = Fd

M = moment - Nm (newton-meters)
F = force - N (newtons)
d = distance - m (meters)

Question 18

What is the equation for calculating pressure?

Answer 18

p = F / A

p = pressure - Pa (pascals)
F = force - N (newtons)
A = area - m^2 (meters squared)

Question 19

What is the equation for calculating pressure in liquid?

Answer 19

p = h * ρ * g

p = pressure - Pa (pascals)
h = height - m (meters)
ρ = density - kg/m3 (kilgorams per
meter cubed
g = gravitational field
strength - N/kg (newtons per
kilogram)