How much does the maximum EMF produced by a generator (a rotating coil) change if the number of turns of the coil is tripled

The reason a penny thrown straight up inside a bus will come back to your hand is that you,the bus,the air inside the bus, and the penny are all moving at the same velocity. true or false

Consider motion in one dimension. (the sign of the vector quantities is their direction indicator.) an object moves in the positive x-direction with speed 2.9 m/s for 4.5 s. it stops for 3.8 s and then moves in the negative x direction with speed 2.8 m/s for 4 s. what is the total distance traveled by the object in units of meter? enter a number with two digits behind the decimal point.

1. do the particles in the medium material move in the same direction of the wave or at opposite direction to the wave? explain your answer. 2. by inputting more energy into the wave, i.e a large shake of the spring, which wave property also increases? 3. are there forces of friction acting while a wave is passing through a medium?