zigya tab
Advertisement

An object experiences a net zero external unbalanced force. Is it possible for the object to be travelling with a non-zero velocity? If yes, state the conditions that must be placed on the magnitude and direction of the velocity. If no, provide a reason.


Yes, even when the net external force is zero, an object may travel with non-zero velocity. 

A rain drop falls downwards with a constant velocity. The net force on the drop is zero because the weight of the drop is balanced by the upthrust and the viscosity of air. 

1852 Views

Advertisement

Explain, why is it difficult for a fireman to hold a hose, which ejects large amounts of water at a high velocity.


Water is ejected with a large forward force (action) and due to reaction, the fireman experiences a large backward thrust. Therefore, the force experienced by him makes it difficult in holding the hose. 

251 Views

When a carpet is beaten with a stick, dust comes out. Explain why?


When a carpet is beaten with a stick, it comes into motion. But the dust particles continue to be at rest due to inertia and get detached from the carpet. 

2044 Views

Why it is advised to tie any luggage kept on the roof of a bus with a rope?


When a bus takes sharp turn on the road, a sudden jerk is felt. As a result of the sudden jerk, the luggage may fall down from the roof because of its tendency to continue moving in the original direction. In order to avoid this, the luggage is tied with a rope on the roof. 

1302 Views

A batsman pushes a cricket ball which then roll on a level ground. After covering a short distance, the ball comes to rest. The ball slows to a stop because

(a) the batsman did not hit the ball enough.

(b) velocity is proportional to the force exerted on the ball.

(c) there is a force on the ball opposing the motion.

(d) there is no unbalanced force on the ball, so the ball would want to come to rest.


The ball comes to a stop because,
(c) There is a force on the ball opposing the motion. 

1092 Views

Advertisement