45mph is the answer if you do the math right
Answer:

Explanation:
The net force exerted on the mass is the sum of tension force and the external force of gravity.

is the tension force.
is the force of gravity.

where
is the rope's radius from the fixed point.
From the net force equation above:

Hence the tension force is 6.046N
Answer:

Explanation:
As we know that moment of force is given as

now we have


now from above formula we have

here we know that

so we have


Answer:
a) force between them is attraction, b) F = 1.125 10⁻² N
Explanation:
In this case the electric force is given by Coulomb's law
F =
In the exercise they give us the values of the loads
q1 = - 10 mC = -10 10⁻³ C
q2 = 5 mC = 5 10⁻³ C
d = 20 cm = 0.20 m
let's calculate
F = 9 10⁹
F = 1.125 10⁻² N
To find the direction of the force we use that charges of the same sign repel each other, as in this case there is a positive and a negative charge, the force between them is attraction
Initially, the velocity vector is
. At the same height, the x-value of the vector will be the same, and the y-value will be opposite (assuming no air resistance). Assuming perfect reflection off the ground, the velocity vector is the same. After 0.2 seconds at 9.8 seconds, the y-value has decreased by
, so the velocity is
.
Converting back to direction and magnitude, we get 