A pickup truck moves at 25 m/s toward the east. Ahmed is standing ...

[Sportsfan2111]

A pickup truck moves at 25 m/s toward the east. Ahmed is standing in the back and throws a baseball in what to him is the southwest direction at 28 m/s (with respect to the truck).
 
  A person at rest on the ground would see the ball moving how fast in what direction?

Question 2

The energy efficiency of a device is
 
  A) the total energy put into the device divided by its useful energy output.
  B) its thermal energy output divided by the total energy put into the device.
  C) its total energy output divided by the total energy put into the device.
  D) its useful energy output divided by the total energy put into the device.
  E) the total energy put into the device divided by its thermal energy output.

[b614102004]

Answer to Question 1

20 m/s at 15 east of south

Answer to Question 2

D