Question

In a lab, four balls have the same velocities but different masses.

Answer 1

Answer:

B

Explanation:

Answer 2

Answer:

New Momentum of Ball B$=13.2 \frac{\mathrm{kgm}}{\mathrm{s}}$

Explanation:

Given:

Mass of Ball A=1kg

Mass of Ball B= 2kg

Mass of Ball C=5kg

Mass of Ball D=7kg

Velocities of A=B=C=D=2.2$\frac{m}{s}$

Momentum of Ball A=2.2$\frac{k g m}{s}$

Momentum of Ball B=4.4 $\frac{k g m}{s}$

Momentum of Ball C=11$\frac{k g m}{s}$

Momentum of Ball D=15$\frac{k g m}{s}$

To Find:

Change in Momentum When of Ball B gets tripled

Solution:

Though all balls have same velocity, thus we get

Velocities of A=B=C=D=2.2$\frac{m}{s}$

Initial Momentum of Ball B=4.4$\frac{k g m}{s}$

If the Mass of Ball B gets tripled;

We get New Mass of Ball B=3×Actual Mass of the ball

                                            =3×2=6kg

Thus we get Mass of Ball B=6kg

According to the formula,  

Change in momentum of Ball B $\Delta p=m \times \Delta v$

Where $\Delta p$=change in momentum

          m=mass of the ball B

         $\Delta v$=change in velocity ball B

And $\Delta v=v,$ since all balls, have same velocity

Thus the above equation, changes to

         $\Delta p=m \times v$

Substitute all the values in the above equation we get

         $\Delta p=6 \times 2.2$

                     $=13.2 \frac{\mathrm{kgm}}{\mathrm{s}}$  

Result:

 Thus the New Momentum of ball B$=13.2 \frac{\mathrm{kgm}}{\mathrm{s}}$