Answer:
-4.0 N
Explanation:
Since the force of friction is the only force acting on the box, according to Newton's second law its magnitude must be equal to the product between mass (m) and acceleration (a):
(1)
We can find the mass of the box from its weight: in fact, since the weight is W = 50.0 N, its mass will be

And we can fidn the acceleration by using the formula:

where
v = 0 is the final velocity
u = 1.75 m/s is the initial velocity
t = 2.25 s is the time the box needs to stop
Substituting, we find

(the acceleration is negative since it is opposite to the motion, so it is a deceleration)
Therefore, substituting into eq.(1) we find the force of friction:

Where the negative sign means the direction of the force is opposite to the motion of the box.
Answer:
<h2>1.17 m/s²</h2>
Explanation:
The acceleration of an object given it's mass and the force acting on it can be found by using the formula

f is the force
m is the mass
From the question we have

We have the final answer as
<h3>1.17 m/s²</h3>
Hope this helps you
Answer:
attached below is the free body diagram of the missing illustration
Initial kinetic energy of the electron = 3 eV
Explanation:
The conclusion that can be drawn about the kinetic energy of the electron is

E
= initial kinetic energy of the electron
E
= -4 eV
E
= -1 eV
insert the values into the equation above
= -1 -(-4) eV
= -1 + 4 = 3 eV
Because you have to study about electricity, first of all, and also need to study about polarity