If a boy running against a wind with speed $2 m / s$ reaches the finish line of a $100 m$ race in 15 seconds. How long will he take to complete the race in absence of wind.

11 s

No worries! We‘ve got your back. Try BYJU‘S free classes today!

11.5 s

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

11.8 s

No worries! We‘ve got your back. Try BYJU‘S free classes today!

12 s

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is B $11.5 s$
If speed of boy is $v_{b}$ and speed of wind is $v_{w} = 2 m / s$
Then, $v_{b} - 2 = \frac{100}{15} \Rightarrow v_{b} = \frac{130}{15} m / s$
time in absence of wind, $t = \frac{100}{v_{b}} = \frac{100 \times 15}{130}$
$t = 11.5 s$

Suggest Corrections

Similar questions

Q. If a boy running against a wind with speed

2 m / s

reaches the finish line of a

100 m

race in 15 seconds. How long will he take to complete the race in absence of wind.

Q. Ramesh could run a 100-m race in 20 seconds. After training, he can finish the race in 15 seconds. By how much has he improved his speed?

Q. A man runs for 100 m in 50 s and then rests for 10 s. If he participates in a 500 m race, how much time will he take to complete the race?

Q. Usain bolt completed a 100 m race in 10 seconds. What was the speed he was running at?

Suppose two friends’ Vignesh and Sarosh decided to have a 100m race such a way that Vignesh runs in the direction in which wind is flowing and Sarosh in the direction opposite to the wind, they ran with the same speed but Vignesh completed the 100m first. The wind flows with a speed of 10m/s.Sarosh complained of the disadvantage he had because he had run against the wind. So both guys went to Gautham to sort it out. Gautham supported Vignesh saying there will be no wind effect on the speed and both made fun of Sarosh.Is Gautham's judgement true or false?

Join BYJU'S Learning Program

If a boy running against a wind with speed 2 m/s reaches the finish line of a 100 m race in 15 seconds. How long will he take to complete the race in absence of wind.

The correct option is B 11.5 sIf speed of boy is vb and speed of wind is vw=2 m/s Then, vb−2=10015⇒vb=13015 m/s time in absence of wind, t=100vb=100×15130 t=11.5 s

If a boy running against a wind with speed $2 m / s$ reaches the finish line of a $100 m$ race in 15 seconds. How long will he take to complete the race in absence of wind.

The correct option is B $11.5 s$
If speed of boy is $v_{b}$ and speed of wind is $v_{w} = 2 m / s$
Then, $v_{b} - 2 = \frac{100}{15} \Rightarrow v_{b} = \frac{130}{15} m / s$
time in absence of wind, $t = \frac{100}{v_{b}} = \frac{100 \times 15}{130}$
$t = 11.5 s$