The hardest part of the job is to find the right formula to use, and write it down. You've already done that ! The rest is just turning the crank until an answer falls out.
You wrote. E = m g h.
Beautiful.
Now divide each side by (g h), and you'll have the formula for mass:
m = E / (g h).
You know all the numbers on the right side. Just pluggum in, do the arithmetic, and you'll have the mass.
Answer:
A
Explanation:
I guess but not sure cause wind is soemthing you can get back electricity is soemthing you can't
Gravity slows the upward speed of any rising object by 9.8 m/s every second.
If the ball is tossed upward at 20 m/s, then it's at the top of its arc and its speed has dwindled to zero in (20/9.8) = 2.04 seconds.
During that time, its starting speed is 20 m/s and its ending speed is zero, so its AVERAGE speed all the way up is (1/2) (20 + 0) = 10 m/s .
Sailing upward for 2.04 seconds at an average speed of 10 m/s, the ball rises to (2.04 x 10) = <em>20.4 meters.</em>
