Which of the following would be the best radiator of thermal energy?
A) a shiny surface
B) a perfectly white surface
C) a perfectly black surface
D) a metallic surface
E) styrofoam
Question 2
A boy jumps at a speed of 20.0 m/s at an angle of 25.0 above the horizontal. What is the horizontal component of the boy's velocity?
A) 18.1 m/s
B) 15.6 m/s
C) 8.5 m/s
D) 12.6 m/s
E) 20.0 m/s