Question

A $10kg$ wagon is pushed with a force of $7N$ for $1.5$ second, then with a force of $5N$ for $1.7$ seconds, and then with a force of $10N$ for $3$ second in the same direction. What is the total change in velocity brought about?

• A. $9.8m/s$
• B. $19.6m/s$
• C. $4.9m/s$
• D. $10m/s$

Answer 1

The correct option is C $4.9m/s$

change in velocity by

First force is $F_1{t}_1/m=7\times 1.5/10=1.05m/s$

by second force is $F_2{t}_2/m=5\times 1.7/10=0.85m/s$

by third force is $F_3{t}_3/m=10\times 3/10=3m/s$

Total change brought in the velocity$=1.05+0.85+3=4.9m/s$

Option C is correct.