A boy can throw a ball with a net force of 55N. How much greater will the acceleration be when he throws a 1kg softball as compared to when he throws a 7kg bowling ball?

the duration of a photographic flash is related to an rc time constant, which is 0.100 μs for a certain camera.

the doppler effect is used by weather forecasters to measure 

moving clouds

the kind of relationship between atmospheric  density and altitude is inverse relationship. this means a surge in either will cut the other factor. density is mass per unit volume, it is hard to compute with only altitude 1,291 kilometers given. also, we could also use temperature and pressure to resolve density but they are not delivered.