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.
<span>The work output of a machine divided by the work input is the "Efficiency" of the machine.
Hope this helps!</span>
One plants don't orbit the sun, the earth does.
two true if its saying plants orbit the sun
Answer:
<em>The range is 35.35 m</em>
Explanation:
<u>Projectile Motion</u>
It's the type of motion that experiences an object projected near the Earth's surface and moves along a curved path exclusively under the action of gravity.
Being vo the initial speed of the object, θ the initial launch angle, and
the acceleration of gravity, then the maximum horizontal distance traveled by the object (also called Range) is:

The projectile was launched at an angle of θ=30° with an initial speed vo=20 m/s. Calculating the range:



The range is 35.35 m