Question

A car attains a velocity of 72 km/hr within 10 sec from aninitial velocity of 54km/hr.Calculate its acceleration and displacement.

Answer 1

Answer:

acceleration is 0.5 m per second

displacement is 175 m .

Step-by-step explanation:

$acceleration = \frac{v - u}{t} \\ \\ = \frac{(72 - 54)}{10} \times \frac{1000}{3600} \\ \\ = \frac{18}{36000} \times 1000 \\ \\ = 0.5 \: m {s}^{ - 2} \\ \\ v = 72 \times 1000 \div 3600 = 20 \: m \: per \: second \\ \\ u = 54 \times 1000 \div3 600 = 15m \: per \: second \\ \\ {v}^{2} - {u}^{2} = 2as \\ \\ s = \frac{ {v}^{2} - {u}^{2} }{2a} \\ \\ = \frac{ {20}^{2} - {15}^{2} }{2 \times 0.5} \\ \\ = \frac{400 - 225}{1} \\ \\ = 175 \: m.$