Question

A
motorcyclist
drives from
from place A to B
with a uniform speed of 30 km/hr and returns from
B to A with a uniform speed 20 km/hr.Find average and velocity. ​

Answer 1

Answer:

average speed = 30+20÷2

=25

Explanation:

average velocity is zero

starts and ends in the same point

Answer 2

Question

A motorcyclist drives from place A to B with a uniform speed of 30 km/hr and returns from B to A with a uniform speed 20 km/hr. Find average speed and velocity.

Solution-

A motoryclist drives from A to B at an average speed of 30 km/h and returns back at an average speed of 20 km/h.

We have to find the average speed and average velocity of the motorcyclist.

Now,

Average speed is defined as the ratio of total distance covered with respect to total time taken. Whereas average velocity is defined as the ratio of total displacement with respect to total time taken.

As the distance covered by the motorcyclist is same i.e. x km. From A to B distance covered is x km and from B to A distance covered is x km. So, the total distance covered by the motorcyclist is 2x km.

As the initial and final points are same. So, total displacement is 0 km.

Also,

Time = Distance/Speed

t1 = x/30 hr and t2 = x/20 hr

Total time taken = t1 + t2

= x/30 + x/20

= x/10(1/3 + 1/2)

= x/10(5/6)

= x/12

Average speed = 2x/(x/12)

= (2*12)

= 24

Therefore, the average speed of the motorcyclist is 24 km/hr.

Average velocity = 0/(x/12)

= 0

Therefore, the average velocity of the motorcyclist is 0 km/hr.