The Gravitational PE (U) depends on three things: the object’s mass (m), its height (h), and gravitational acceleration (g), which is 9.81 m/s^2 on Earth’s surface.
so U = mgh = 9.81mh on earth
mass of the car = 50.0 grams = 0.05kg
height, h:
Hill 1 = 90.0 cm = 0.9m,
Hill 2 = 65.0 cm = 0.65m,
Hill 3 = 20.0 cm = 0.2m
substitute into eqn U = mgh
U @ top of Hill 1 = 0.05*9.81*0.9 = 0.4415J
U @ top of Hill 2 = 0.05*9.81*0.65 = 0.3188J
U @ top of Hill 3 = 0.05*9.81*0.2 = 0.0981J
difference in Gravitational Potential Energy from the top of Hill 1 to the top of Hill 3 = 0.4415 - 0.0981
= 0.3434J where J is the unit for energy, Joules
Answer: 2
Explanation: bro this is literally basic knowledge
The chemical reaction that would represent the combustion of methane would be CH4 + 2O2 = CO2 + 2H2O. Combustion reactions are reactions which involves a substance burning in oxygen.
Answer:
at r < R;
at 2R > r > R;
at r >= 2R
Explanation:
Since we have a spherically symmetric system of charged bodies, the best approach is to use Guass' Theorem which is given by,
(integral over a closed surface)
where,
= Electric field
= charged enclosed within the closed surface
= permittivity of free space
Now, looking at the system we can say that a sphere(concentric with the conducting and non-conducting spheres) would be the best choice of a Gaussian surface. Let the radius of the sphere be r .
at r < R,
= 0 and hence
= 0 (since the sphere is conducting, all the charges get repelled towards the surface)
at 2R > r > R,
= Q,
therefore,
(Since the system is spherically symmetric, E is constant at any given r and so we have taken it out of the integral. Also, the surface integral of a sphere gives us the area of a sphere which is equal to
)
or, 
at r >= 2R
= 2Q
Hence, by similar calculations, we get,

All objects in orbit must follow the path of an ellipse (one of Keplers laws)