Question

Find out the magnitude of the change in momentum of the object between $t=0$ and $t=0.4$ sec from the given graph between Total force acting on an object vs Time ?

• A. $2kg-m/sec$
• B. $5kg-m/sec$
• C. $10kg-m/sec$
• D. $12kg-m/sec$
• E. $15kg-m/sec$

Answer 1

The correct option is E $15kg-m/sec$

We know that $F=\frac{dp}{dt}$

$⟹\int dp=\int Fdt$

$⟹\Delta p$=Change in momentum=$\int Fdt$= Area under the given curve for given interval of time.

Thus $\Delta p=\frac{1}{2}\times 0.2\times 100+(0.4-0.2)\times 25=15kg-m/s$