Chapter 4, Problem 47A

To determine

Whether the statement given by J or Jo is correct or not.

Answer to Problem 47A

The statement given by J is correct.

Explanation of Solution

Introduction:

Newton’s Second law,

  $a=\frac{F_{net}}{\text{mass}}$

And,the acceleration of an object is given by,

  $a=\frac{\Delta v}{\Delta t}=\frac{v_f-v_i}{t_f-t_i}$

Where $v_f$ and $v_i$ are the final and initial velocities of the object at the time $t_f$ and $t_i$ , respectively.

Using the above formula, if the net horizontal force acting on the cart is in the right direction, then the net acceleration of the cart will also be in the right direction. Hence, the cart will be moving inthe right direction as said by J.

Now, using the formula of acceleration, the direction of the velocity of the cart is the same as that of the acceleration. Hence, the acceleration and the velocity of the cart will be towards right only.

Conclusion:

Thus, the statement given by J that the cart will be moving towards the right direction is correct while the statement given by Jo that the cart will be moving in either direction is incorrect.