Question

Give reqsons
i. Why is a plumbline used by builders?

ii. If you kick a ball across a playing field, are the forces on the ball balanced or
unbalanced? Why?

iii. If you use some modelling clay to make a large boat shape, it will float. If you
roll the same amount of modelling clay into a ball, it will sink. Why is this?

iv. Why a parachute comes down to the ground slowly?​

Answer 1

Answer:

Explanation:

i)

Until the modern age,plumb bobs were

used on most tall structures to provide vertical datum lines for the building measurements. As the building proceeded upward,the plumbline would also be taken higher,still centered on the datum.

ii)

The forces acting unbalanced.This is because when we kick the ball then we apply a certain unbalanced force which is greater than the frictional force and thus the ball.

iv)

when a parachute is released,the weight pulls down on the strings. The large surface area of the parachute material provides air resistance to slow the parachute down. The larger surface area the more air resistance and the slower the parachute will drop.

hope it's help you:)