alleryStart learning →A motor receives 100 J; 30 J becomes heat, with no other losses. Mechanical output?
A30 J
B130 J
C70 J
D100 J
Answer & Solution
Correct answer: C. 70 J
Conservation of energy leaves 100 − 30 = 70 J as mechanical output.
Keep practising Work, Energy and Power
Browse all Work, Energy and Power questions for ICSE Class 8, or explore more Physics topics.
Related questions
B steadily lifts twice A's mass through half A's height in twice A's time. Useful lifting A gives 100 W for 5 s; B gives 40 W for 20 s. Which transfers more energy?A ball has KE 20 J and GPE 30 J. With no losses, GPE falls to 10 J. New KE?A body drops from rest through 5 m without air resistance. Final speed? g = 10 m/s².Unequal masses have equal GPE above ground. Dropped from rest without air, faster at grounBodies of 4 kg and 1 kg have equal kinetic energy. Speed ratio heavy:light?Mass becomes three times as large and speed halves. Kinetic energy becomes?A 50 W device runs for 3 minutes at that power. Energy transferred?