Hewitt 35.5-35.9 hw review

When we investigate time dilation, we find that time is

• stretched due to motion
• compressed due to motion
• like the speed of light, a constant in nature
• nature's way of seeing that everything does not happen at once

What is the maximum value of v1v2/c^2 in an extreme situation? What is the smallest value?

• Maximum infinite, minimum 0
• Maximum 1, minimum 0
• Maximum infinite, minimum -infinite
• Maximum 1, minimum -1

Is the relativistic rule V = (v1 + v2) /(1 + v1v2/c^2) consistent with the fact that light can have only one speed in all uniformly moving reference frames? How?

• Yes. If either v1 or v2 is equal to c, then V = c.
• Yes, but only if both v1 and v2 are equal to c does this reduce to V = c.
• No. If v1 or v2 is equal to c, then this does not reduce to V = c.
• No. If both v1 and v2 are equal to c, then this does not reduce to V = c.

What is the universal standard of time?

• The Earth frame of reference
• There is none.
• The galaxy frame of reference
• The Sun frame of reference

The hypothetical twin trip featured in the book states that a traveling twin would return to her Earth-bound twin

• actually younger
• hypothetically older
• hypothetically younger
• actually older

How long would a meterstick appear to be if it were traveling like a properly thrown spear at 99.5% of the speed of light?

• 1 m
• 1/2 m
• 1/10 m
• 2 m

How long would the meterstick in the preceding question appear to be if it were traveling with its length perpendicular to its direction of motion?How long would the meterstick in the preceding question appear to be if it were traveling with its length perpendicular to its direction of motion?

• 1/10 m
• 1/2 m
• 1 m
• 2 m

If you were traveling in a high-speed rocket ship, would metersticks on board appear to you to be contracted? Defend your answer.

• Yes. All moving objects experience length contraction in the direction of motion.
• No. Space contracts, but physical objects do not.
• Yes. All moving objects experience length contraction regardless of the direction of motion and the frame of reference.
• No. The stick is in your frame of reference.

A friend in a spaceship moves away from you at 0.5c, and then fires a rocket also away from you at 0.5c relative to the spaceship. From your frame of reference, the speed of the fired rocket is

• c, the speed of light
• greater than c
• 0.8c
• 0.5c

What would be the momentum of an object if it were moving at the speed of light?

• The momentum would be simply mc.
• The momentum would be zero.
• The momentum would be infinite.
• The momentum would be mc^2.