Question

A ship of mass 3 × 10⁷ kg initially at rest is pulled by a force of 5 × 10⁴ N through a distance of 3 m. Assuming that resistance due to water is negligible, the speed of ship is

• A. 0.2 ms^-1
• B. 0.1 ms^-1
• C. 1 ms^-1
• D. 2ms ^-1

Answer 1

Answer: (B)

0.1 ms^-1

Answer 2

b)

Sol. Using F = ma, we get

a = $\frac { \mathrm { F } } { \mathrm { m } } = \frac { 5 \times 10 ^ { 4 } } { 3 \times 10 ^ { 7 } } = \frac { 5 } { 3 } \times 10 ^ { - 3 }$ again using 2 as = v² – u², we get

2 × $\frac { 5 } { 3 } \times 10 ^ { - 3 }$ × 3 = v²