Question

Q. 4. A body is moving with a velocity of 20 m/s. A force acts on it for 5 sec and its final velocity becomes 40 m/s. Find the acceleration and the distance travelled by the body in 5 sec.

Answer 1

Solution :

⏭ Given:

✏ Initial velocity of body = 20mps

✏ Time interval = 5s

✏ Final velocity = 40mps

⏭ To Find:

1. Acceleration
2. Distance travelled

⏭ Calculation:

• Acceleration

$\mapsto \sf \: \underline{\red{ v = u + at}} \\ \\ \mapsto \sf \: 40 = 20 + 5a \\ \\ \mapsto \sf \: 5a = 20 \\ \\ \mapsto \sf \: a = \dfrac{20}{5} \\ \\ \mapsto \: \boxed{ \sf \pink{a = 4 \: m {s}^{ - 2}}} \: \gray{ \bigstar}$

• Distance travelled

$\mapsto \sf \: \underline{ \blue{d = ut + \dfrac{1}{2}a {t}^{2} }} \\ \\ \mapsto \sf \: d = (20 \times 5) + \dfrac{1}{2} (4 \times 25) \\ \\ \mapsto \sf \: d = 100 + 50 \\ \\ \mapsto \: \boxed{ \green{ \sf{d = 150 \: m}}} \: \gray{ \bigstar}$

⏭ Additional information:

• Acceleration and velocity are vector quantities.
• Acceleration can be positive, negative and zero.
• Displacemen is also vector quantity.