an object Travels number. A to point B which page 54 kilometre per hour and returns from point B to point A with 72 kilometre per hour what is the average speed and average velocity of the particle
Answers
Correct Question
An object travels from A to B point with a speed of 54 kilometre per hour and returns from point B to point A with a speed of 72 kilometre per hour. What is the average speed and average velocity of the particle?
Solution -
Let us assume that the object covers 'd' distance.
Case 1)
An object travels from A to point B with a speed of 54 km/hr.
Distance = d and speed = 54 km/hr = 15 m/s
Distance = Speed × Time
d = 15 × t1
d/15 = t1
Case 2)
The object returns from point B to point A witha speed of 72 km/hr or 20 m/s.
d = 20 × t2
d/20 = t2
Average speed is defined as the ratio of the total distance covered with respect to total time taken.
From point A to B distance travelled is d and from point B to A is also d. So, total distance travelled is 2d.
Average speed = 2d/(t1 + t2)
= 2d/(d/15 + d/20)
= 2d(4d+3d/60)
= (2d × 60)/7d
= 17.4 m/s
Similarly,
Average velocity is defined as the ratio of the total displacement with respect to total time taken.
As the initial and final points of the object are same. So, total displacement is zero.
Average velocity = 0/(d/15 + d/20) = 0 m/s.
Answer:
Explanation:
Solution :-
Let us take distance be d.
We know that,
Distance = Speed × Time
So,
According to the Question,
1st case,
d = 15 × t₁
t₁ = d/15 ..... (i)
And,
2nd case,
d = 20 × t₂
t₂ = d/20 ...... (ii)
We know that,
Average speed = Total Distance/Total time taken
= 2d/(d/15 + d/20)
= 2d/(4d + 3d/60)
= 2d/(7d/60)
= 2d × 60/7d
= 17.4 m/s.
Hence, the average speed is 17.4 m/s.
Now, Average velocity,
Here, displacement is zero.
Hence, the average velocity will also be zero.