physics energy equations

Question 1

what is the equation for work done?

Answer 1

W = Fs

Question 2

what is the equation for weight?

Answer 2

W = mg

Question 3

what is the equation for gravitational potential energy?

Answer 3

Eg = mgh

Question 4

what is the equation for kinetic energy?

Answer 4

Ek = 1/2 m (v x v)

Question 5

what is the equation for elastic potential energy?

Answer 5

Ee = 1/2 k (e x e)

Question 6

what is the equation for efficiency of energy?

Answer 6

efficiency = useful output energy / total input energy

Question 7

what is the equation for power?

Answer 7

P = E/t

Question 8

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

Answer 8

5 x 50 = 250j

Question 9

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

Answer 9

49/9.8 = 5kg

Question 10

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)

Answer 10

120/9.8 x 150 = 0.08kg

Question 11

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

Answer 11

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

Question 12

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

Answer 12

0.5 x 5 x 0.04 = 0.1j