A train travels at an average speed of 15 m/s.

a) Express its average speed in km/h

b) Find the time in sec taken by the train to travel 750m

15 m/s * 1km/1000m * 3600s/hr = 15*3600/1000 km/hr

750m * 1s/15m = 750/15 s

mujhy yai sawal samaj mai nahi a rha pls help:(

To solve these questions, we will use the following formula:

Speed = Distance / Time

a) To express the average speed of the train in km/h, we need to convert m/s to km/h.

1 kilometer = 1000 meters
1 hour = 3600 seconds

So, to convert m/s to km/h, we will multiply the speed by (3600/1000):

Average speed (km/h) = Average speed (m/s) * (3600/1000)

In this case, the average speed is 15 m/s. Let's substitute this value into the formula:

Average speed (km/h) = 15 m/s * (3600/1000)

Now, let's calculate the result:

Average speed (km/h) = 15 * 3.6 = 54 km/h

b) To find the time taken by the train to travel 750m, we rearrange the formula to solve for time:

Time = Distance / Speed

In this case, the distance is 750m, and the speed is 15 m/s. Let's substitute these values into the formula:

Time = 750m / 15 m/s

Now, let's calculate the result:

Time = 50 seconds

Therefore, it takes 50 seconds for the train to travel 750m.

as alam alikum