No force is necessary to keep a moving object moving (in a straight line at a constant speed).
Uranus takes 84 earth years to make a full rotation around the sun<span />
There are missing data in the text of the problem (found them on internet):
- speed of the car at the top of the hill:

- radius of the hill:

Solution:
(a) The car is moving by circular motion. There are two forces acting on the car: the weight of the car

(downwards) and the normal force N exerted by the road (upwards). The resultant of these two forces is equal to the centripetal force,

, so we can write:

(1)
By rearranging the equation and substituting the numbers, we find N:

(b) The problem is exactly identical to step (a), but this time we have to use the mass of the driver instead of the mass of the car. Therefore, we find:

(c) To find the car speed at which the normal force is zero, we can just require N=0 in eq.(1). and the equation becomes:

from which we find
9. Compounds can form from two nonmetals by sharing their electrons in a
C) covalent
11. An atom that has an excess positive or negative electrical charge caused by the loss or addition of an electron is called a(n) ______.
B) ion
5 is either A or C
Answer:
a) Temperatura, b) Temperature, c) Constant
, d) None of these
, e) Gibbs enthalpy and free energy (G)
Explanation:
a) the expression for ideal gases is PV = nRT
Temperature
b) The internal energy is E = K T
Temperature
c) S = ΔQ/T
In an isolated system ΔQ is zero, entropy is constant
Constant
d) all parameters change when changing status
None of these
e) Gibbs enthalpy and free energy