Question

A person runs at a constant speed around a 100m diameter circular track and completes each lap in 60 sec. What is the magnitude of the runner's average velocity for one fourth of a lap?

Answer 1

1.31 m/s

Step-by-step explanation:

t = 60sec

d= 100m, r = d/2 = 100/2 = 50m

distance = Circumference= 2πr = 314.2m

one fourth of a lap, d= 314.2/4 = 78.55 m

v = s/t = 78.55/60 = 1.31 m/s

Answer 2

As, we know that,

• C= 2πr, while the diameter of the circle provide is 100 m.So, we can calculate the the "r" and the "C" by putting the different values in the above equation.
• "r", is the radius, r of the same circle that is calculates the distance from the center of the circle to one of the points on the circumference of the same circle. Which is calculated as follow;
• The diameter of the circle is diameter=100 m. And the "r" will be half of that, as r=50 m.
• So, for the C=?, we have to put all the required values in the equation:
• C=2×(3.14)×(50),
• C=314 meters.

• So, if the initial point,d₁ as d₁=1 meter and while the final point d₂, is d₂=314 meters,

• Time, t₂= 60 seconds and the initial time,t₁=0 second, then:
• Then Δv=d₂-d₁/t₂-t₁,
• Δv=314-235.5/60-0, 78.5
• Δv=1.3 m/sec,⇒ The required answer.

Step-by-step explanation:

• Average velocity,v(avg):

When the total displacement, Δd covered by a body in between any two points is measured and then divided upon the total time, t taken is called as the average velocity,Δv.

• Mathematical formula:

1. Δv=d₁+d₂/t₁+t₂,
2. Units: m/sec,