Which of the following mathematical formulas best describes the relationship between the original age of
the child (A) the age of the child when the message
was received (R) and their distance from the receiver in
light years (D)?
O A = RD
A = R/D
O A = R+D
0 A-D-R
A+R-D

The speed of light in a material is 0.50 c. what is the critical angle of a light ray at the interface between the material and a vacuum?

Two cannon balls weighing 18 kg and 24 kg are chained together and fired horizontally with a velocity of 165 m/s from the top of a 21-m wall. the chain breaks during the flight of the cannonballs and the 18-kg cannonball strikes the ground at t = 1.5 s, at a distance of 240 m from the foot of the wall, and 7 m to the right of the line of fire. determine the position of the other cannonball at that instant. neglect the resistance of the air.

Aweather forecaster uses doppler radar to predict the track of a storm near the town of meadowlands. when the doppler signal is pointed at the storm from the town's center, the frequencies of the waves appear to be decreasing. what should the weather forecaster predict? a. that the storm will move around the edges of meadowlands without hitting the tosis center o b. that residents should be prepared, because it is impossible to know whether the storm will hit o c. that the storm is moving toward meadowlands and that residents should be prepared d. that the storm is moving away from meadowlands and is not likely to hit the town