Question 245: Laws of Motion

Question

Sand is being dropped on a conveyer belt at the rate of M kg/s. The force necessary to keep the belt moving with  a constant velocity of $$\upsilon $$ m/s will be :

Accepted Answer

$$F = {d \over {dt}}\left( {Mv} ight) = v{{dM} \over {dt}} + M{{dv} \over {dt}}$$
As v is a constant,
$$F = v{{dM} \over {dt}}$$
But $${{dM} \over {dt}} = M\,kg/s$$
$$ 	herefore $$ To keep the conveyer belt moving at v m/s,
force needed = vM newton.

Answer

$${{Mv} \over 2}$$ newton

Answer

zero

Answer

M$$v$$ newton

Answer

2 M$$v$$ newton

Laws of Motion

Sand is being dropped on a conveyer belt at the rate of M kg/s. The force necessary to keep the belt moving with a constant velocity of $\upsilon $ m/s will be :

Choose the correct answer: