The diameters of the main rotor and tail rotor of a single-engine helicopter are 7.65 m and 1.05 m, respectively. the respective rotational speeds are 454 rev/min and 4,130 rev/min. calculate the speeds of the tips of both rotors. compare these speeds with the speed of sound, 343 m/s.

A250-n box is at rest on a frictionless horizotal floor. then a person shoves the box with a non-zero force of magnitude p. which statement best describes the relationship betweeen p and the motion of the box after it was shoved? -the box will not move when p< 250n but otherwise will accelerate at a constant rate that is directly proportional to p - the box will begin moving at a speed that is directly proportional to p, then will gradually slow to a halt -the box will move with constant velocity at a speed that is directly proportional to p -box will accelerate across the floor at a constant rate that is directly proportional to p