According to the formula

Where a is work, f is force and d is the distance that box was moved over. And from that formula, you can get that f = a/d and that is 54.83N of force
Answer:
θ_c = 36.87°
Explanation:
Index of refraction for index medium; n_i = 2
Index of refraction for Refractive medium; n_r = 1.2
Formula to find the critical angle is given;
n_i(sin θ_c) = n_r(sin 90)
Where θ_c is critical angle.
Thus;
2 × (sin θ_c) = 1.2 × 1
(sin θ_c) = 1.2/2
(sin θ_c) = 0.6
θ_c = sin^(-1) 0.6
θ_c = 36.87°
Kinetic, thermal and electrical. There is more then one form of energy
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.