Question

A particle Travels first half distance with uniform is speed of 14 metre per second and next half distance with uniform speed 80 metre per second calculate the average speed

Answer 1

Answer:

average speed = 1120/47 m/s = 23.8m/s

Explanation:

let total distance = 2x

for first half distance (that is x)

speed = 14m/s

=> time = t(1) = distance ÷ speed

=> t(1) = (x/14)s

for next half distance (that is x)

speed = 80m/s

=> time = t(2) = distance÷ speed

=> t(2) = (x/80)s

total time of journey = t = t(1) + t(2)

=> t = (x/14) + (x/80)

taking LCM

=> t = { (x × 40) + (x × 7) } ÷ ( 560)

=> t = { 40x + 7x } ÷ 560

=> t = 47x ÷ 560

now,

total time = 47x/560 s

total distance = 2x

average speed = distance ÷ time

average speed = 2x ÷ (47x/560)

average speed = 2×560 ÷ 47

average speed = 1120/47 m/s = 23.8m/s