Answer:
Explanation:
It is given that,
Mass of the grindstone, m = 3 kg
Radius of the grindstone, r = 8 cm = 0.08 m
Initial speed of the grindstone, 
Finally it shuts off, 
Time taken, t = 10 s
Let 
is the angular acceleration of the grindstone. Using the formula of rotational kinematics as :
Let 
is the number of revolutions of the grindstone after the power is shut off. Now using the third equation of rotational kinematics as :
or
So, the number of revolutions of the grindstone after the power is shut off is 50.
<h2>It will take 0.125 seconds to reach the net.</h2>
Explanation:
Initial speed, u = 34 ft/s = 10.36 m/s
Acceleration, a = -9.81 m/s²
Displacement, s = Final height - Initial height = 8 - 4 = 4 ft = 1.22 m
We have equation of motion, s = ut + 0.5 at²
Substituting
s = ut + 0.5 at²
1.22 = 10.36 x t + 0.5 x -9.81 x t²
4.905t² - 10.36 t + 1.22 = 0
t = 1.99 s or t = 0.125 seconds
Minimum time is 0.125 seconds.
It will take 0.125 seconds to reach the net.
Well, it depends. Your latitude on Earth--that is, how close you are to the equator--and the time of year make a difference. I'll explain why. Your motion is made up of four pieces: the rotation of the Earth on its axis, the motion of the Earth around the Sun, the Sun's orbit about the center of the galaxy, and the motion of the whole galaxy.
