Give a reason for the following questions:
i. It is difficult to balance our body when we accidentally step on a peel of a banana.
ii. Pieces of bursting crackers fall in all possible directions.
iii. A glass pane of a window is shattered when a flying pebble hits it.
iv. It is easier to stop a tennis ball than a cricket ball moving at the same speed.
v. A javelin thrower is marked foul if an athlete crosses over the line marked for the throw.
Athletes often fail to stop themselves before the line.
Answers
Answer:
(i) The reason is that one cannot exert action force effectively on the slippery peel of banana in the backward direction. Hence, in response, the ground does not exert sufficient reaction force in forward direction and hence we lose our balance.
(ii) This can be explained by the law of conservation of momentum. When due to explosion some pieces move in the same particular direction, then in order to conserve momentum, the remaining pieces move in the opposite direction.
(iii) The reason is that, the glass pane of the window is a hard solid. The flying pebble suffers change in momentum in a very short time, so the force exerted by the glass window on the pebble will be large. Consequently the glass pane of the window will shatter.
(iv) The reason is that mass of the cricket ball is more than that of a tennis ball. Thus, momentum is more in case of the cricket ball due to larger mass as compared to the tennis ball. So, less force has to be applied in the case of the tennis ball to stop.
(v) The reason is that when athletes are running for the throw then due to inertia of motion they often fail to stop themselves before the line.