In order to know how long it has been falling for you take the final velocity "49m/s" and divide it by the acceleration "9.8m/s" and get 5, since you have been using seconds in the calculations the answer is 5 seconds. (Fun fact, it is actually 9.82m/s per second since it accelerates and they rounded it down.)
Answer:
Explanation:
a )
moment of inertia of hollow ball
= 2 / 3 mR² , m is mass and R is radius of the ball
= 2 / 3 x 120 x .5²
= 20 kg m²
b )
5 rpm = 5 / 60 rps
n = .0833
angular velocity ω = 2πn= 2 x 3.14 x .0833= .523 rad /s
angular acceleration = increase in angular velocity / time
= .523 - 0 / 20
α = .02615 rad /s²
c )
Torque = moment of inertia x angular acceleration
= 20 x .02615
= .523 Nm
d )
θ = 1/2 α t²
= .5 x .02615 x 20²
= 5.23
2π n = 5.23 where n is required number
n = .83
All elements are balanced. There are 1 Mg, 1 O, 2 Li's and 2 Cl's.
A fatter handle. This allows you to provide more torque to the screw, which should eventually loosen it.
The block on the action of two forces, the Force of Friction and the Tangential Weight. Using the Newton's Secound Law, we have:
Using the Velocity Hourly Equation, we get:
Uniting the equations:
Entering the unknowns:

Obs: Approximate results
If you notice any mistake in my english, please let me know, because i am not native.