Sand is falling on a flat car being pulled with constant speed. The rate of mass falling on the cart is constant. Then the horizontal component of force exerted by the falling sand on the cart (sand particles sticks to the cart)

Options

A. Increases
B. decreases
C. remains constant
D. increases and then decreases

Explanation

The horizontal component of velocity sand just before falling on the cart is `v_(s)=0`
The horizontal speed of cart `=v_(c)`(constant).
The rate of mass falling on cart `=mu`(constant).
Horizontal force exerted by falling sand on cart `=mu v_(rel)=mu(v_(c)-v_(s))=muv_(c)`
`:' mu` and `v_(c)` are constant, the horizontal force is constant.