W=f*deltax
f=ma
a=9.8(gravitational acceleration)
(7)(9.8)=68.6n
w=(68.6)(54)=3704.4J
0.75 km = (0.75×100000) cm = 75000 cm
The scientific notation to find this is ---
Kilo-Hecto-Deca-Meter-Deci-Centi-Milli
Gravitational Potential Energy (GPE) = 9.8m/s² (rate of gravity) x 8,000,000kg of water x 50.0m
GPE = 3,294,000,000 Joules (J) which is also the change in GPE
<span>A centripetal force is a force which keeps an object moving in a circle. When the ball is at the top position, let's assume that the speed v is such that the gravitational force is precisely equal to the required centripetal force to keep the ball moving around in a circle. Then the string will not go slack.
centripetal force = force of gravity on the ball
m v^2 / r = m g
v^2 / r = g
v^2 = g r
v = sqrt { g r }
v = sqrt { (9.80~m/s^2) (0.7 m) }
v = 2.62 m/s
The minimum speed of the ball at the top position is 2.62 m/s</span>