91Ó°ÊÓ

• Mass,$m=0.4\text{ k²µ}$
• The average velocity expression is,$v_{avg,x}=\frac{v_{ix}+v_{fx}}{2}$

Average speed is the ratio of distance covered in a particular period of time.

(a)

Acceleration due to gravity$a=g=−9.8\text{ â¶Ä³¾}/{\text{s}}^{\text{2}}$

The net force will be calculated as,

$\begin{array}{l}F=ma\\ F=0.4×\left(−9.8\right)\\ F=−3.92\text{ N}\end{array}$

The net force is –3.92 N.

(b)

Thenet force does have only the y-direction component, which means that only the y component will change.

(c)

Thenet force does not have only an x-direction component, which means that only it does not change. It remains constant.

(d)

Thenet force does not have an x and z component, so that momentum in that directions, it does not change and in the y-direction has a negative value. So it will be deceased.

(e)

Thenet force does not have only a z-direction component, Due to which there is no Z moment change in the component. It remains constant.

(f)

The given expression $v_{avg,x}=\frac{(v_{ix}+v_{fx})}{2}$in the question does not valid for the motion at a constant rate. The speed of the ball is small compared to the speed of light.