2. There is shift in sound
frequency for observers towards
whom the source is approaching.

A. a downward
B. an upward
C. no

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.

b. lifting dumbbell weight at 20-degree angle from the body after a 45-degree angle

answercollision;