Question

A boy walks a distance of 100 meters to the right at a steady speed of 1.00 m/s. Then he stops for 30 seconds. Then returns back and walks for 2 minutes to the left at speed of 1.5m/s.

Calculate the total time of his round trip.
Calculate the total distance.
Calculate the total displacement.
Calculate the average speed.
Calculate the average velocity

Answer 1

Step-by-step explanation:

`speed=(Distance)/(time)`

In the figure attached:

A boy travels AB distance of 100 m, with speed of 1.00 m/s

AB = 100 m

`1.00 m/s=(100 m)/(t_1)`

`t_1=100 s`

After reaching at point B he stops there at for 30 seconds.

`t_2= 30 s`

After , 30 seconds he he comes back to his initial position that is A with steady speed of 1.00 m/s.

Distance covered from B to A= 100 m

Time taken by him during coming back=
`t_3`

`1.00=(100 m)/(t_3)`

`t_3=100 s`

After returning to to point A he turns left and moves towards point C with speed of 1.5 m/s for 2 minutes.

Distance of AC = ?

`t_4=2 min= 120 s`

`1.5 m/s=(AC)/(120 s)`

AC = 180 m

The total time of his round trip is:T

`T=t_1+t_2+t_3+t_4=100 s+30 s(stop)+ 100 s(returning)+120 s=350 s`

The total distance: D

D = AB + BA (returning) + AC=100 m + 100 m + 180 m = 380 m[/tex]

The total displacement of boy:

Displacement is the shortest distance between the initial point and final point.

He first walked to point B from A and then came back to A . And after that walking to point C from A.So, the final displacement (d) is from A to C.

d = AC = 180 m

The total displacement of boy is 180 m.

The average speed of the boy is given by:

`=(AB+BA+AC)/(t_1+t_2+t_3+t_4)=(D)/(T)`

`(D)/(T)=(380 m)/(350 s)=1.085 m/s`

The average velocity of the boy is given by:

`=(AC)/(t_1+t_2+t_3+t_4)=(d)/(T)`

`(d)/(T)=(180 m)/(350 s)=0.5142 m/s`