Hi there!
Recall the following:

k = Coulomb's Constant (Jm/C²)
q = Charge (C)
r = distance between charges (m)
To calculate the electric force between the two charges, we can simply divide by another 'r' (distance):

Answer:
A. Heat flows from an object at higher temperature to an object at lower temperature
Explanation:
The option A obeys the 2nd law of thermodynamics. The heat will flow from the object at higher temperature to the object at Lower temperature till they reach an equilibrial state.
Heat doesn’t necessarily flow from an object with higher thermal energy to an object with lower thermal energy because an object has a higher thermal energy when it’s mass is more than the other. This makes B wrong.
C is wrong because heat moves from an object with higher temperature to objects with Lower temperature regardless of the state of matter.
Answer:
Explanation:
it is a vector as it has a magnitude and a direction. If it was a scalar quantity it would just have a magnitude and would be 45 m. Acceleration is an example of a vector quantity
Answer:
7772.72N
Explanation:
When u draw your FBD, you realize you have 3 forces (ignore the force the car produces), gravity, normal force and static friction. You also realize that gravity and normal force are in our out of the page (drawn with a frame of reference above the car). So that leaves you with static friction in the centripetal direction.
Now which direction is the static friction, assume that it is pointing inward so
Fc=Fs=mv²/r=1900*15²/55=427500/55=7772.72N
Since the car is not skidding we do not have kinetic friction so there can only be static friction. One reason we do not use μFn is because that is the formula for maximum static friction, and the problem does not state there is maximum static friction.
The universe has trillions of galaxies and counting. Astronomers give names to each galaxy base on its shape (e.i, Sombrero galaxy, Milkyway Galazy, ect,.).
Also, the size of the galaxy is taken into account and their color.