I think it was Isaac Newton
Answer:



Explanation:
<u>Simple Pendulum</u>
It's a simple device constructed with a mass (bob) tied to the end of an inextensible rope of length L and let swing back and forth at small angles. The movement is referred to as Simple Harmonic Motion (SHM).
(a) The angular frequency of the motion is computed as

We have the length of the pendulum is L=0.81 meters, then we have


(b) The total mechanical energy is computed as the sum of the kinetic energy K and the potential energy U. At its highest point, the kinetic energy is zero, so the mechanical energy is pure potential energy, which is computed as

where h is measured to the reference level (the lowest point). Please check the figure below, to see the desired height is denoted as Y. We know that

And

Solving for Y



The potential energy is


The mechanical energy is, then


(c) The maximum speed is achieved when it passes through the lowest point (the reference for h=0), so the mechanical energy becomes all kinetic energy (K). We know

Equating to the mechanical energy of the system (M)

Solving for v


Answer:
Net force is Zero.
Explanation:
If all forces that are equal and opposite are exerted on an object the resulting force will be Zero.
Answer:
so angular velocity is 7.13128 sec−1
Explanation:
velocity v = 2.2 m/s
displacement s = 220 mm = 0.220 m
distance d = 510 mm = 0.510 m
to find out
angular velocity
solution
we know that
angular velocity will be velocity ( v) / (displacement² + distance²) .....1
now put all these value in equation 1 and we get angular velocity i.e.
angular velocity = velocity ( v) / (displacement² + distance²)
angular velocity = 2.2 / (0.22² + 0.51²)
angular velocity = 2.2 / 0.3085
angular velocity = 7.13128
so angular velocity is 7.13128 sec−1
Solution:
We have,
Power [P] = 25000 Watt
Mass [m] = 6000 kg
Height [h] = 20 metres
Time [t] = ?
Now,
P = W/t = F x d/t = mxgx h/t
Or, 25000 = 6000 x 10 x 20/25000 [.......g = 10
m/s^2]
Or, t = 6000 x 10 x 20/25000
Or, t = 1200/25
Therefore, t = 48 second
Hence, the required time for the crane to lift the load is 48 seconds.