How long will a man take to go one round a circular track of radius 4.2m.if he runs at an speed of 6km\h.

Pie*diameter, divided by speed. (22/7*4.2*2)/6 hours.

8500

To calculate the time it takes for the man to go one round on a circular track, you need to use the formula for calculating the circumference of a circle. The formula is:

Circumference = 2 * π * radius

First, let's convert the speed from kilometers per hour to meters per second, as the circumference of the track is given in meters. To do this, divide the speed of 6 km/h by 3.6 to get the equivalent speed in meters per second:

Speed (m/s) = Speed (km/h) / 3.6

Speed (m/s) = 6 km/h / 3.6 = 1.67 m/s (rounded to two decimal places)

Next, substitute the given radius into the formula to find the circumference of the track:

Circumference = 2 * π * radius
Circumference = 2 * 3.14 * 4.2 m
Circumference = 26.52 m (rounded to two decimal places)

Now, divide the circumference of the track by the speed to find the time it takes to complete one round:

Time = Circumference / Speed
Time = 26.52 m / 1.67 m/s
Time = 15.87 seconds (rounded to two decimal places)

Therefore, it will take approximately 15.87 seconds for the man to go one round on the circular track.