The radius of the curved road at the given condition is 54.1 m.
The given parameters:
- <em>mass of the car, m = 1000 kg</em>
- <em>speed of the car, v = 50 km/h = 13.89 m/s</em>
- <em>banking angle, θ = 20⁰</em>
The normal force on the car due to banking curve is calculated as follows;

The horizontal force on the car due to the banking curve is calculated as follows;

<em>Divide </em><em>the second equation by the first;</em>

Thus, the radius of the curved road at the given condition is 54.1 m.
Learn more about banking angle here: brainly.com/question/8169892
Answer:

Explanation:
The period of a physical pendulum is:



The length of the leg is approximately the height of the person:

The period is:


I think it’s the first one
Kinetic energy is related to velocity by:
KE = (1/2)mv^2
solve for mass m
10 = (1/2)m(10)^2
10 = (1/2)m(100)
10= 50m
10/50 = m
1/5 = m
at 20 km/hr
KE = (1/2)(1/5)(20)^2
KE = (1/10)(400)
KE = 40 J