Answer:
218.5 N
Explanation:
In order for the sled to be in equilibrium along the vertical direction, the forces acting along this direction must be balanced. So the equilibrium equation is:

where
N is the normal force
F = 50 N is the force that pulls the sled
is the angle between the force and the horizontal, so
is the component of F acting along the vertical direction
(mg) is the weight of the sled, with
m = 25 kg being the mass of the sled
g = 9.8 m/s^2 is the acceleration due to gravity
Solving the formula for N, we find

Gravitational potential energy<span> is </span>energy<span> an object possesses because of its position in a </span>gravitational<span> field. </span><span>The equation for </span>gravitational potential energy<span> is GPE = mgh.
GPE = 1200(1.6)(350) = 672000 J
Hope this answers the question. Have a nice day.</span>
To solve this problem we will use the ratio given by the amount of total charge (q) equivalent to the individual charge of each electron (e) multiplied by the total number of electrons (n) present, that is,

Here
q = Total charge
e = Electron charge
Our value of the charge is

We know that the charge in a electron is

Replacing we have then



Therefore the number of electrons needed to form a charge of -2nC is 