Answer:
F = 1300 N
Explanation:
F = mv²/R = 0.4(100²)/3 = 1333.3333...
Answer: 810 J
Explanation: work W = F·s = 101 N · 8.0 m = 808 J
Force F = u mg = 101 N in which u is friction constant. Also mass is included in force.
When t=2, the ball has fallen d(2) = 16 (2²) = 64 feet .
When t=5, the ball has fallen d(5) = 16 (5²) = 400 feet .
Distance fallen from t=2 until t=5 is (400 - 64) = 336 feet.
Time period between t=2 until t=5 is (5 - 2) = 3 seconds.
Average speed of the ball from t=2 until t=5 is
(distance covered) / (time to cover the distance)
= 336 feet / 3 seconds = 112 feet per second.
That's what choice-C says.
