Question

d. 60.3%
16. The wheel of an engine 14.28m in circumference makes four revolutions in 7 seconds.
Determine the speed of the train
a. 30 kmph
b. 25 kmph
C. 15 kmph
d. 20 kmph
est-3​

Answer 1

Solution :

Circumference of the wheel = 14.28 m

In four revolutions, it goes

= 4 * 14.28 m

= 57.12 m

In 7 s, it goes 57.12 m [ ATQ ]

In 1 s, it goes (57.12 ÷ 7) m = 8.16 m

∴ in 1 hour = 3600 seconds, it goes

= 8.16 * 3600 m

= 29376 m

= 29.376 km

≈ 30 km

Thus, the speed of the train is 30 kmph

∴ option (a) is correct.