Question

A bus with kids and a truck with their bags started moving from the school to the camp at the same time. The speed of the bus was 60 mph. The speed of the truck was 45 mph. It took kids 3 hours to reach the camp. How long did they have to wait for their bags?

Answer 1

1

Explanation:

Answer 2

1 hour

Explanation:

The distance covered by each of the two vehicle can be written as

`d=vt`

where

d is the distance covered

v is the speed of the vehicle

t is the time elapsed

For the bus, the speed is

`v_b = 60 mph`

So the distance covered by the bus in a time t is

`d=60t` (1)

The kids in the bus took 3 hours to reach the camp,

t = 3 h

So the distance between the school and the camp is:

`d=(60)(3)=180 mi`

For the truck, the speed is

`v_t=45 mph`

So the distance covered by the truck in a time t is

`d=45t` (2)

Since the distance to cover is 180 miles, the time taken by the truck is

`t=(d)/(45)=(180)/(45)=4 h`

And so, the truck arrives

`\Delta t = t_t - t_b = 4 h - 3 h = 1 h`

1 hour after the bus.