Bennett Mechanical Work and Energy Questions and Answers Flashcards
6 cards from real Bennett Mechanical Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Bennett Mechanical Work and Energy Questions and Answers flashcards as text
A 20 N force pushes a box 5 meters in the direction of the force. How much work is done?
Answer: 100 J
Work equals force multiplied by distance (W = F × d = 20 × 5 = 100 J).
Which unit is used to measure energy in the SI system?
Answer: Joule
The joule (J) is the SI unit of energy, equal to one newton-meter.
A spring with a spring constant of 200 N/m is compressed by 0.1 m. What is the elastic potential energy stored?
Answer: 1 J
Elastic PE = ½kx² = ½ × 200 × (0.1)² = 1 J.
A 5 kg object is lifted to a height of 10 m. What is its gravitational potential energy? (g = 10 m/s²)
Answer: 500 J
Gravitational PE = mgh = 5 × 10 × 10 = 500 J.
A machine is 80% efficient and receives 500 J of input energy. How much useful output energy does it deliver?
Answer: 400 J
Useful output = efficiency × input = 0.80 × 500 = 400 J.
Power is defined as which of the following?
Answer: Work done per unit time
Power is the rate at which work is done, calculated as work divided by time (P = W/t).