Question

A constant force acting on a body 5kgfor 2sec. it increase it's velocity from 3m/sec to 7m/sec find the force applied .if this force is applied for 5sec then calculate the final velocity of the body.
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Answer 1

Answer:

The final velocity of the body is 13 m/s.

$\large\underline\mathrm\blue{GIVEN \: :}$

Mass, m = 5 kg

Initial velocity, u = 3 m/s

Final velocity, v = 7 m/s

time, t = 2 sec.

$\large\underline\mathrm\red{FORMULA \: :}$

Acceleration, $\sf a \: = \: \dfrac {(v-u)}{t}$

Here,

u = Initial velocity

v = final velocity

t = time taken.

$\large\underline\mathrm\orange{TO \; FIND \: :}$

• The velocity of the body.

$\large\underline\mathrm\green{SOLUTION \: :}$

put the values in the formula,

→ $\sf a \: = \: \dfrac {(7-3)}{2}$

→ $\sf a \: = \: \dfrac {4}{2} \: = \: 2 \: m/s^{2}$

Force = $\sf mass \times acceleration$

$\sf F \: = \: m \times a$

→ $\sf 5 \times 2 \: = \: 10 \: N.$

$\sf Final \: velocity, \: v \: = \: 3 + 2 \times 5$

$\sf v \: = \: 13 \: m/s.$

$\therefore$ The final velocity of the body is 13 m/s.