D= vt +.5at^2
since he started at rest, v (initial velocity) is 0
so d=.5at^2
d = .5 (6m/s^2) (4.1s)^2
then put that into a calculator.
Answer:37 J
Explanation:
Given
Step :1
Heat added Q=44 J
Work done=-20 J

Step :2
Heat added Q=-61 J
work done 



as the process is cyclic


work done in compression is 37 J
Answer:B
Explanation:
Magnetic field lines form close loops and never intercept
The ball can't reach the speed of 20 m/s in two seconds, unless you THROW it down from the window with a little bit of initial speed. If you just drop it, then the highest speed it can have after two seconds is 19.6 m/s .
If an object starts from rest and its speed after 2 seconds is 20 m/s, then its acceleration is 20/2 = 10 m/s^2 .
(Gravity on Earth is only 9.8 m/s^2.)