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 1000 W motor runs for 30 seconds. How much energy does it consume?
Answer: 30,000 J
Energy = Power × time = 1000 × 30 = 30,000 J.
Which form of energy is stored in a stretched rubber band?
Answer: Elastic potential energy
A stretched rubber band stores elastic potential energy due to its deformation.
A 2 kg object moves at 4 m/s. What is its kinetic energy?
Answer: 16 J
KE = ½mv² = ½ × 2 × 4² = 16 J.
According to the law of conservation of energy, what happens to total energy in a closed system?
Answer: It remains constant
Energy cannot be created or destroyed; it only changes form, so total energy in a closed system is constant.
A 60 W light bulb operates for 2 hours. How much energy does it consume?
Answer: 432,000 J
Energy = 60 W × (2 × 3600 s) = 60 × 7200 = 432,000 J.
Work is only done on an object when an applied force causes what?
Answer: Displacement
Work requires both a force and displacement in the direction of that force; no movement means no work.