Electric Energy = Current x Voltage x time = 207 x 9.4 = 1,945.8 J
mass of the ball m = 0.63 kg
initial height h = 1.8 m
final height h ' = 3.03 m
initial speed v = 7.09 m / s
final speed v ' = 4.21 m / s
Let the work done on the ball by air resistance W = ?
we know from law of conservation of energy ,
total energy at height h + work done by air = total energy at height h '
mgh + ( 1/ 2) mv^ 2 + W = mgh ' + ( 1/ 2) mv'^ 2
0.630*9.8*1.8 + 0.63*7.09^2 + W = mgh ' + ( 1/ 2) mv'^ 2
From there you can find W
if there is negative sign indicates it work opposite direction to motion
Answer:
Explanation:
I ASSUME you mean acceleration is 3 m/s²
v² = u² + 2as
s = (v² - u²) / 2a
s = (18² - 12²) / (2(3))
s = 30 m
to verify we can see that the acceleration time is
t = (18 - 12) / 3 = 2 s
s = 0 + 12(2) + ½(3)2² = 30 m
