Question

Q4) A car acquires a velocity of 20m/s in 10 s from rest.
Calculate (i) acceleration (ii) average velocity (iii) distance travelled.

Answer 1

Explanation:

initial velocity,u=0

final velocity,v=20

timetaken,t=10s

$acceleration \: = \frac{change \: in \: velocity}{time} \\ = \frac{v - u}{t} \\ = \frac{20 - 0}{10 } \\ = \frac{20}{10} \\ = 2 \frac{m}{sec}$

$average \: velocity = \frac{total \: displacement}{total \: time}$

total displacement will be initial it will be zero as the body is at rest

velocity =displacement/time

20=d/10

200=d

$average velocity = \frac{200}{10} \\ \\ = 20ms$

Answer 2

Answer:

(i) 2 m/s^2    (ii) 20m/s     (iii) 200m

Explanation:

(i) Acceleration(a)= Change in velocity/Time

                            = (v-u)/t

                            = (20-0)/10

                            = 20/10

                            = 2 m/s^2

(iii) Distance,

                   20m covered in 1s

                   200m covered in 10s

(ii)Avg. Velocity= Distance/Time

                         = 200/10

                         = 20 m/s