Work & energy worksheet with answers

Free printable Work & energy worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

New worksheetPractise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
80 kgh = 15 mt = 60 s

A hoist lifts an 80 kg load at constant speed through a height of 15 m in 60 s. Find the average power P it delivers to the load, in W.

m = 80 kgh = 15 mt = 60 sg = 9.81 m/s²
P = W
2.Easy
400 kgh = 26 mt = 12 s

A hoist lifts a 400 kg load at constant speed through a height of 26 m in 12 s. Find the average power P it delivers to the load, in kW.

m = 400 kgh = 26 mt = 12 sg = 9.81 m/s²
P = kW
3.Medium
30°L = 1 m2 kg

A 2 kg ball hangs on a light string of length 1 m. It is pulled aside until the string makes 30° with the vertical and released from rest. Find the tension T in the string when the ball passes the lowest point.

m = 2 kgL = 1 mθ = 30°g = 9.81 m/s²
T = N
4.Medium
35°d = 7 mμ = 0.3

A block slides from rest down a slope at 35° to the horizontal. The coefficient of kinetic friction is 0.3. Find its speed v after it has slid 7 m along the slope.

θ = 35°μ = 0.3d = 7 mg = 9.81 m/s²
v = m/s
5.Hard
8 kg3 kgμ = 0.15d = 2.5 m

An 8 kg block rests on a rough horizontal table (μ = 0.15). A light string runs from it over a smooth pulley at the edge of the table to a hanging 3 kg block. The system is released from rest. Find the speed v of the blocks after the hanging block has dropped 2.5 m.

m1 = 8 kgm2 = 3 kgμ = 0.15d = 2.5 mg = 9.81 m/s²
v = m/s
6.Hard
h = 5 mL = 5 mμ = 0.15k = 2500 N/m

A 4 kg block is released from rest at height 5 m on a smooth ramp. At the bottom it crosses a rough horizontal strip 5 m long (μ = 0.15) and then runs onto a spring (k = 2500 N/m) on a smooth surface. Find the maximum compression x of the spring.

m = 4 kgh = 5 mL = 5 mμ = 0.15k = 2500 N/mg = 9.81 m/s²
x = cm

Answer key

  1. 1. P = 196.2 W
  2. 2. P = 8.502 kW
  3. 3. T = 24.88 N
  4. 4. v = 6.71 m/s
  5. 5. v = 2.833 m/s
  6. 6. x = 36.53 cm

Full step-by-step solutions: practise this topic on examproblems.com.