Running on a treadmill is slightly easier than running outside because there is no drag force to work against. Suppose a 60 kg runner completes a 5.0 km race in 17 minutes. Determine the drag force on the runner during the race. Suppose that the cross section area of the runner is 0.72 m2.

Drag force = 2.20N.

Explanation:

Given data:

Weight of the runner = 60kg

Distance completed by the runner = 5km

Time spent to cover the distance = 17 minutes.

Cross sectional area = 0.72m^2.

Density of air = 1.2kg/m^3.

Solution:

V = d/t

Where d = 5km

t = 17 mins

V = (5*103)/(17*60)

= 5.1m/s

The drag force experienced by a person

Fd = 1/2 p C A v2

= 1/2 * 1.2 * 1 * 0.72 * 5.1

= 2.20N

f = f = Fd / m g

f = 2.20 / (60 * 9.8)

= 3.74*10^-3

hi i’m sorry to call us today so we will get back with y’all and we will have to do it haha omg was the day

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s