Aboy with a mass of 60 kg climbs 10 m
vertically up a ladder.
a) what is his weight?
b) how much work is done?
c) what are the energy changes here?

Two identical small charged spheres are a certain distance apart, and each one initially experiences an electrostatic force of magnitude f due to the other. with time, charge gradually leaks off of both spheres. when each of the spheres has lost half its initial charge, the magnitude of the electrostatic force will be

Athermometer is removed from a room where the temperature is 70° f and is taken outside, where the air temperature is 10° f. after one-half minute the thermometer reads 60° f. what is the reading of the thermometer at t = 1 min? (round your answer to two decimal places.) ° f how long will it take for the thermometer to reach 30° f? (round your answer to two decimal places.)

What is relative velocity? in which condition is relative velocity known by adding the velocity of the first body and that of the second body