A hydraulic lift lifts a 1,150 kg car at the rate of 3 cm per second. calculate:
a) the power of the elevator.
b) the work done in one minute.
Sol.:
a) 338.1 Watts
b) 20286 Joules​

The star betelgeuse is about 600 light-years away. if it explodes tonight, a. we'll know because debris from the explosion will rain down on us from space.b. we'll know it immediately because it will be brighter than the full moon in the sky.c. we won't know about it until 600 years from now.d. none of the above.