Alarm clock 1 is positioned at x = -d and alarm clock 2 at x = +d in reference frame A. According to a clock in reference frame A, both go off at t = 0. An observer in reference frame B, which is moving relative to A, measures alarm clock 2 as going off first. In what direction is B moving relative to A?

Suppose that k and x are both known to be four-vectors and that in every inertial frame k is a multiple of x. That is, k = λx in frame S, and k' = λ'x' in frame S', and so on. Then the factor λ (the "quotient" of k and x) is in fact a four-scalar with the same value in all frames, λ = λ'. Prove this quotient rule.

Write S if the group of words is a sentence or F if it is a sentence fragment.

Their helmets were topped by tall red plumes.

Why is identifying the frame of reference important in describing motion?

Identify the following sentence as a phrase fragment (PF), clause fragment (CF), run-on sentence (RO), or complete sentence (C).

One writer reported visiting a factory where the managers wore color-coded badges these indicated the wearer's personality type according to the personality test the person had taken.

What is a frame of reference? How is it used to measure motion?

Identify if the sentence below is incomplete. Then, reconstruct the sentence fragment as a complete sentence.

Dined on the prairie and gathered flowers.

Gabor stands on a cart that moves with a constant velocity. In his frame of reference, he tosses a ball vertically up and down. Lutaaq stands on the ground nearby. She also tosses a ball vertically up and down with respect to her frame of reference. (a) Explain what the motion of Gabor's ball looks like from Lutaaq's frame of reference. (b) Explain what the motion of Lutaaq's ball looks like from Gabor's frame of reference.

Recognizing More Fragments. Label each fragment $F$ and each sentence $S$. A bus racing toward the intersection.

What is meant by a super frame in the 802.15.4 Zigbee standard?

What is the axial load in member $B D$ of the frame?

Write S if the group of words is a sentence or F if it is a sentence fragment.

People sitting on the float, waving to the people in the crowd.

A 0.150-kg frame, when suspended from a coil spring, stretches the spring 0.0400 m. A 0.200-kg lump of putty is dropped from rest onto the frame from a height of 30.0 cm. Find the maximum distance the frame moves downward from its initial equilibrium position.

What are the two main purposes of a CTS frame?