physics energy equations Flashcards

1
Q

what is the equation for work done?

A

W = Fs

2
Q

what is the equation for weight?

A

W = mg

3
Q

what is the equation for gravitational potential energy?

A

Eg = mgh

4
Q

what is the equation for kinetic energy?

A

Ek = 1/2 m (v x v)

5
Q

what is the equation for elastic potential energy?

A

Ee = 1/2 k (e x e)

6
Q

what is the equation for efficiency of energy?

A

efficiency = useful output energy / total input energy

7
Q

what is the equation for power?

A

P = E/t

8
Q

if the distance (s) = 5m and the force (F) = 50N what is the work done (j)?

A

5 x 50 = 250j

9
Q

if the weight (W) = 49 and the gravitational field strength (g) is on earth what is the mass?

A

49/9.8 = 5kg

10
Q

if the gravitational potential energy (Eg) = 120, the gravitational field strength (g) is on earth and the height (h) = 150 what is the mass (m)

A

120/9.8 x 150 = 0.08kg

11
Q

if the mass (m) = 1200 the velocity (v) = 20 what is the kinetic energy?

A

0.5 x 1200 x (20 x 20) = 240000j

12
Q

if the spring constant (k) = 5 and the extension (e) = 0.2 what is the elastic potential energy?

A

0.5 x 5 x 0.04 = 0.1j