please help me with this questions thank you so much.
1. A wave completes 44.8 cycles in 11.9 seconds. Find its speed if its wavelengh is 7.77 x 10^3 m?
2. And object moving at 1.225m/s accelerates at 6.611m/s2 for 3.330s. Find work and power, if the object's mass is 55.5 kg?
3. A boulder with m=339kg falls from the top of a cliff. It strikes the ground 2.24 seconds later.
a) How long is the cliff?
b)How much work did gravity do on the boulder as it fall to the ground?