Question

A boy run 200 m in 24 sec. What is his speed in kmper hour

Answer 1

Answer:

29.98 km/h or 30 km/h (approx)

Explanation:

According to the given question,

d = distance = 200 m

t = time = 24 sec

s = speed

And we are asked to find speed in km/h.

We know,

• speed = distance/time

• s = d/t

Putting the values we get,

• s = 200/24

• s = 8.33 m/s

Now, to convert it into km/h,

We know,

• 1 km = 1000 m

• 1 m = 1/1000 km

Similarly,

• 1 sec = 1/3600 hr

• s = 8.33 m/s

• s = 8.33 ×3600 /1000

• s = 29.98 km/h

Thus speed of the boy is 29.98 km/h.

Answer 2

Explanation:

We know that 1km = 1000m

So 1 m= 1/1000km

We have been given 200m .

So 200 m = 200*1/1000= 2/10=0.2 m

Now we know that 1 hr = 60 minutes

Also 1 minute =60 seconds

So 60 min = 60*60 seconds=3600 seconds

Now 1sec = 1/3600 hour

24 seconds= 24*1/3600 = 0.006 hour

We know that v= s/t

So speed = 0.2÷0.006=33.33.....

= 33.34 km/hour