1. An airplane flies with an airspeed (speed relative to the air) of 215 km/h. The wind is blowing at 45.0 km/h. Find the velocity of the
plane (relative to the ground) if the plane is pointed straight west and
the wind is:

A. blowing toward the
west (3 points)

B. blowing toward the east (3 points)

C. blowing toward the south (4 points)
(For part C be sure to calculate the angle as well.)

Matt is driving down 7th street. he drives 150 meters in 18 seconds. assuming he does not speed up or slow down, what is his speed?

30 points - when can a theory be modified if a new type of technology allows for new observations that raise new questions? a. immediately, while the questions about the theory are being asked b. after new hypotheses related to the theory are tested in experiments c. only after the new observations disprove all parts of the theory d. while scientists begin to think about how the theory could improve

Suppose that 27 j of work is needed to stretch a spring from its natural length of 6 m to a length of 9 m. (a) how much work is needed to stretch the spring from 12 m to 14 m? j (b) how far beyond its natural length will a force of 78 n keep the spring stretched?