Question

Consider the following situation. You are riding on a school bus and are juggling three oranges.Ultimately, you wish to analyze the motion of the oranges by applying Newton's laws.

a. give two conditions that must be met for the interior of the bus to be used as an inertial frame of reference

b. if the windows of the bus are covered and the road was perfectly smoooth, would you be able to determine whether or not the bus was moving? Explain?

c. if you analyzed the motion of the oranges while the bus is travelling at 60 miles per hour and again while it is standing still, would you arrive at the same answers.

d. could you get any clues from the motion of the oranges as to whether or not the bus was moving?

e. if the bus driver suddenly slammed on the brakes, slowing the bus from 60 miles per hour to a stop in a few seconds, would you be able to continue to juggle the oranges during the deaceleration of the bus?

f. During the deacceleration of the bus, would it still qualify as an inertial frame of reference.

2. Consider juggling a set of three oranges while seated on a merry-go-round. Would it be possible to analyze the motion of the oranges within the context of an inertial frame of reference?

3. Consider standing on the surface of the earth and juggling three oranges. Since the earth is rotating and orbiting the sun, is it possible to analzye the motion of the oranges within the context of an inertial frame of reference?

Answer 1

I am answering your first complete question.

a) The condition for an inertial frame is that it is not being acted upon by any external unbalanced force. In otherwords the frame should not be accelerating. For this our bus should be moving with constant speed on a smooth road such that no jerky motion occures. These are the two conditions.

b) If the bus is moving with constant speed then we would not be able to find out if the bus is moving or not since we can not compare it with anything outside. So the answer is no

c) Yes since in both the cases bus is inertial the physics should not change.

d) Again if the bus is moving with constant speed the relative velocity of bus with the orange remains constant. And we will not be able to see the motion of the bus with the orange. Here we ignore air resistance felt by the orange.

e) The answer is no. Because now the bus is no more an inertial frame. The orange tend to move at the constant speed of 60 kmph but bus stops so we will see that the orange is accelarating.

f) No. The explaination is same as the explaination in part 'e'. The bus will feel an external force wich will affect the observations made.