The first: alright, first: you draw the person in the elevator, then draw a red arrow, pointing downwards, beginning from his center of mass. This arrow is representing the gravitational force, Fg.
You can always calculate this right away, if you know his mass, by multiplying his weight in kg by the gravitational constant

let's do it for this case:

the unit of your fg will be in Newton [N]
so, first step solved, Fg is 637.65N
Fg is a field force by the way, and at the same time, the elevator is pushing up on him with 637.65N, so you draw another arrow pointing upwards, ending at the tip of the downwards arrow.
now let's calculate the force of the elevator

so you draw another arrow which is pointing downwards on him, because the elevator is accelating him upwards, making him heavier
the elevator force in this case is a contact force, because it only comes to existence while the two are touching, while Fg is the same everywhere
Answer:
a. 
b. 
Explanation:
The force existing between two charges is given as

where q= charge,
k=constant
r= distance between the two charges
Note: this force can either be repulsive or attractive force depending on the charges involve. it is repulsive if they are similar charge and it is attractive if it is opposite charges.
Also the charge of an electron is

A. we first determine the magnitude force between the -4nC and the electron

this force will be repulsive force and it points away from the electron i.e points towards the +ve x-axis
for the -5.50nC the distance between them is 0.600m as can be seen in the diagram the magnitude of the force is

this this force will be repulsive force and it points away from the electron i.e points towards the -ve x-axis.
The total net force on the electron is thus

b. at distance of x=1.20m, this is shown on the diagram below (attachment 2)
we first determine the magnitude force between the -4nC and the electron

this force will be repulsive force and it points away from the electron i.e points towards the +ve x-axis.
for the -5.50nC the distance between them is 0.4m as can be seen in the diagram the magnitude of the force is

this this force will be repulsive force and it points away from the electron i.e points towards the +ve x-axis.
The total net force on the electron is thus

Answer:
I think C
Explanation:
If im right give brainliest :)
The specific heat capacity of different substances vary for the same reason that different substances have different melting and boiling points to one another. If the bonds between atoms are stronger, it will require more energy to heat up the substance.Sep 8, 2018