a car travel at 54 km per hour for first 20 second 36 kilometre per hour for next 30 seconds and finally 18 km per hour for next 10 second find its average speed
Answers
hope this may help to solve the above problem
Hey there!
Formula used:
• Distance = speed * time
• Speed ( in 1 km/h) = 5 /18 (in 1 m/s)
Distance covered when car travels at 54 km/h for first 20 s:
Speed = 54 km / h
= 54 *( 5/18) m/s
= 15 m/s
Distance (d₁) = speed * time
= 15 * 20 = 300 m
Distance covered when car travels at 36 km/h for 30 s:
S = 36 km/h = 36 * (5/18) m / s = 10 m/s
d₂ = v * t = 10 * 30 = 300 m
Distance covered when car travels at 18 km/h for 10 s:
S = 18 km/h = 18*(5/18) m/s = 5 m/s
d₃ = v * t = 5 * 10 = 50 m
Average speed = Total distance(d₁ + d₂ + d₃) / Total time
= (300 + 300 + 50) m / (20 + 30 + 10) s
= (650 m) / 60 s
= 10.83 m/s (←Answer)
Good day!