Question

plz give answers for each of the following

1.Distinguish between speed and velocity.
2.Under what condition is the magnitude of average velocity of an object equal
to its average speed.
3.Rahul swims in a 90m long pool. He covers 180m in one minute by swimming
from one end to the other and back along the straight path .Find the average
speed and average velocity of Rahul.
4.Convert km/hr into m/s
a] 72km/hr b]108km/hr
5.Convert m/s into km/hr
a]30m/s b]50m/s

Answer 1

Answer:

1) Speed is the time rate at which an object is moving along a path

 Velocity is the rate and direction of an object's movement.

2)The magnitude of average velocity of an object is equal to its average speed, only in one condition when an object is moving in a straight line.

3) Distance = 180 m

Time = 1 min = 60sec

Average speed = total distance covered / total time taken

= 180m / 60 sec

= 3m/s

Displacement = 0m/s ( as Rahul come back along the same path so, the initial and final position is same )

Average velocity = displacement/ time

= 0m / 60 s

= 0m/s

4)to convert km/h to m/s we should multiply it with 5/18

a) ==>72 × $\frac{5}{18}$

==> 4 × 5= 20m/s

b)==>108 ×  $\frac{5}{18}$

==> 6 × 5= 30m/s

5) to convert m/s to km/h we should multiply it with 18/5

a) ==>30 ×  $\frac{18}{5}$

==> 6 × 18 = 108km/h

b)==>50 ×  $\frac{18}{5}$

==> 10 × 18 = 180km/h

hope this helps you