A child goes down a playground slide that is inclined at an angle of 27.5° below the horizontal. Find the acceleration of the child given that the coefficient of kinetic friction is .415.

i think the answer would be reserve.

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me