Car travels from A to B at a speed of 40 km/h and returns back at a speed of 60 km/h. Its average speed will be
A. 40 km/h
B. 48 km/h
C. 50 km/h
D. 60 km/h
Answer: Option B
Solution (By Examveda Team)
Understanding Average Speed:Average speed isn't just the simple average of two speeds. It's about the total distance covered divided by the total time taken.
Let's break it down:
Imagine the distance between A and B is 120 km (we can choose any distance, this makes the calculation easy).
Going from A to B:
Speed = 40 km/h
Distance = 120 km
Time = Distance / Speed = 120 km / 40 km/h = 3 hours
Returning from B to A:
Speed = 60 km/h
Distance = 120 km
Time = Distance / Speed = 120 km / 60 km/h = 2 hours
Calculating Average Speed:
Total distance = 120 km + 120 km = 240 km
Total time = 3 hours + 2 hours = 5 hours
Average speed = Total distance / Total time = 240 km / 5 hours = 48 km/h
Therefore, the correct answer is B: 48 km/h
Remember: Average speed depends on both the distance and the time taken for each part of the journey. It's not simply adding the speeds and dividing by two.
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Comments (1)
Newton's Third Law of Motion applies to which of the following situations?
A. When a person jumps from the boat to the river, the boat goes backwards
B. Passengers standing in a bus fall in the back direction, when the stationary bus suddenly moves
C. When a person falls on the cement floor, he gets hurt
D. While catching a fast moving cricket ball, a fielder puts his hands backwards
For every action there is an equal and opposite reaction. The law was given by
A. Isaac Newton
B. Albert Einstein
C. Niels Bohr
D. Duncan Haldane
Newton's second law of motion:
A. Explains the relationship between forces on two mutually effective objects
B. Also known by the law of inertia
C. It is helpful to understand the effects of force
D. Also known by the law of conservation of energy
A. centrifugal force
B. inertia
C. centripetal force
D. gravitational force

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