A rock with a mass of 25 kg is pushed up a 15 meter hill in 62 seconds. How much Power is needed to move the rock?

Aplane flies directly between two cities, a and b, which are separated by . from a to b, the plane flies into a headwind. on the return trip from b to a, the wind velocity is unchanged. the trip from b to a takes less than the trip from a to b. what is the airspeed of the plane, assuming it is the same in both directions

Which of the following are used in an electrochemical cell? a. electrodes b. electrolyte c. terminals d. all of the above

An electromagnetic wave with frequency 65.0 hz travels in aninsulating magnetic material that has dielectric constant 3.64 andrelative permeability 5.18 at this frequency. the electric fieldhas amplitude 7.20 \times 10^{ - 3} {\rm v}/{\rm m}. a. what is the speed of propagation of the wave? b. what is the wavelength of the wave? c. what is the amplitude of the magnetic field? d. what is the intensity of the wave?