Question

A train has speed 60km/h for first one hour and 40km/h for next 1 hour its average speed in kmph is

Answer 1

Given:

• Speed of train for 1st hour = 60km/h
• Speed of train for next 1 hour = 40km/h

To find:

• Average speed

Solution:

★ Using the formula

Avg speed = 2v1v2/v1 + v2

Avg speed = 2(60)(20)/60 + 20

Avg speed = 2400/80

Avg speed = 30km/h

Hence , Average speed of train = 30km/h

★ Knowledge enhancer:

Kinematics: It is a branch of mechanics which studies about motion.

Kinematic equations:

1st equation : v = u + at

2nd equation : s = ut + 1/2at²

3rd equation : v² - u² = 2as