To solve the problem it is necessary to apply the equations related to the conservation of both <em>kinetic of rolling objects</em> and potential energy and the moment of inertia.
The net height from the point where it begins to roll with an inclination of 30 degrees would be



In the case of Inertia would be given by

In general, given an object of mass m, an effective radius k can be defined for an axis through its center of mass, with such a value that its moment of inertia is



Replacing in Energy conservation Equation we have that
Potential Energy = Kinetic Energy of Rolling Object




Therefore the correct answer is C.
Answer:
1. 10.5 Kg
2. s/g
Explanation:
1. Determination of the mass of gasoline
Density of gasoline = 0.7 Kg/L
Volume of gasoline = 15 L
Mass of gasoline =?
The density of a substance is simply defined as the mass of the substance per unit volume of the substance. Mathematically, the density of a substance can be expressed as:
Density = mass / volume
With the above formula, we can obtain the mass of the gasoline as follow:
Density of gasoline = 0.7 Kg/L
Volume of gasoline = 15 L
Mass of gasoline =?
Density = mass / volume
0.7 = Mass of gasoline / 15
Cross multiply
Mass of gasoline = 0.7 × 15
Mass of gasoline = 10.5 Kg
2. Density has various units some are listed below:
I. Kilogram per litre (Kg/L)
II. Kilogram per cubic metre (Kg/m³)
III. Milligram per millilitre (mg/mL)
IV. Gram per millilitre (g/mL)
V. Gram per cubic centimetre (g/cm³)
Considering the options given in the question above, it is evident that second per gram (s/g) is not a unit of density because density is mass per unit volume.


The results may differ due to resistive forces that may be affecting the system by decelerating it or any other external forces that might accelerate it a bit.Or the timing could be a little inaccurate.