Question

A body initially at rest is moving with uniform acceleration $a$. Its velocity after $n$ second is $\upsilon$ . The displacement of the body in $2 s$ is:

• A. $\frac{2\upsilon (n-1)}{n}$
• B. $\frac{\upsilon (n-1)}{n}$
• C. $\frac{\upsilon (n+1)}{n}$
• D. $\frac{2\upsilon (n+1)}{n}$

Answer 1

Answer: (A)

$\frac{2\upsilon (n-1)}{n}$

Answer 2

Displacement in last $2$ second $=\frac{1}{2}a{{n}^{2}}-\frac{1}{2}a{{(n-2)}^{2}}$ $=2a(n-1)$ Acceleration $a=\frac{\upsilon }{n}$ $(\because t=ns)$ Displacement in last $2s=\frac{2\upsilon (n-1)}{n}$