Question

On a conveyor belt moving with a speed u, sand falls at a constant rate $\frac{dm}{dt}$ where m is the mass of sand. The extra force required to maintain the speed of

• A. $m\frac{du}{dt}$
• B. mu
• C. $\frac{dm}{dt}/u$
• D. $u\frac{dm}{dt}$
• E. $\frac1{m} \frac{du}{dt}$

Answer 1

Answer: (B)

mu

Answer 2

The correct option is (B) : mu