Question

A car starts from city A and it travels 50 km in a straight line to city B. Immediately it turns around, and returns to city A. It took 2 hours for this round trip. The average speed of the car for this round trip is: (a) 0 km/h (b) 25 km/h (c) 50 km/h (d) 100 km/h

Answer 1

Given,

A car travels from city A to city B( 50 km) and then again returns to city A.

Total time taken in this journey = 2 hours

To Find,

The average speed of the car.

Solution,

The formula for calculating the average speed is

Average speed = Total distance/ Total time taken

Since the car travels from city A to B and then again returns from B to A.

Total Distance = 100 km

Time taken = 2 hours

Average speed = 100/2

                          = 50 km/h

Hence, the average speed of the car is 50 km/h.

Answer 2

AVERAGE SPEED OF CAR IS 50 km/hr (Option c)

Given:

• Distance between A and B = 50 km
• Total time taken = 2 hours

To find:

• Average speed of car ?

Calculation:

Average speed is defined as the total distance divided by the total time taken by the object.

$avg. \: s = \dfrac{distance}{time}$

• Total distance in this case will be (50+50) = 100 km (i.e. from A to B and again from B to A)

$\implies avg. \: s = \dfrac{50 + 50}{2}$

$\implies avg. \: s = \dfrac{100}{2}$

$\implies avg. \: s = 50 \: kmph$

So, average speed of car is 50 km/hr (option c).