Chapter 3, Problem 20A

If you're in a smooth-riding bus that is going at 40 km/h and you flip a coin vertically, how fast does the coin move horizontally while in midair?

To determine

The horizontal speed of coin in midair when it is tossed in the bus.

Answer to Problem 20A

The horizontal speed of a coin is 40 km/h, same as a bus speed.

Explanation of Solution

Introduction:

The object in motion remains in motion as stated by the law of inertia.

On Earth every object is moving with the earth.

When a coin is tossed, its horizontal motion before and later is same as the bus speed. Only the vertical motion of coin is affected by force of gravity. So, the horizontal speed of coin is same as the bus speed i.e. 40 km /h.

Conclusion:

The horizontal speed of a coin is 40 km/h same as a bus speed.