How is the frictional force produced? please answer my question in simple language..

Which statement is true? a) the work done to lift an object 6 meters is greater than the gravitational potential energy it gains. b) the work required to push an object is less than the work required to pull an object the same distance. c) the work required to raise an object to a height is equal to the gravitational potential energy the object gains. d) the work done against gravity to lift an object straight up is greater than the work required to roll it up a ramp.

Using the black numbers on the stopwatch to answer the questions. what is the most accurate reading of seconds as indicated by the long second hand? a. 5.3 b. 5.6 c. 7.2 d. 53 secs its for edg i found out it was 5.3 and tenth of seconds freebie

Which wave would cause destructive interference at every point of the wavelength and completely cancel out the wave?