For this case we have that by definition:

Where,
- <em>m: mass of the object
</em>
- <em>a: acceleration of the object
</em>
- <em>F: summation of forces
</em>
We have then:

Then, by clearing the acceleration we have:

Substituting values we have:

Answer:
The acceleration of the box is equal to:

To calculate the force between two negative charges, we use the formula which is given by the Coulomb`s Law as

Here,
and
are the charges on the pith balls, r is the separation between the charges and k is constant and its value is
.
Given
and
.
Substituting these values in above formula we get,

Thus, the repulsive force between two pith balls is
.
The SI prefix that means 1/100 is centi.
Explanation:
upthrust is the same as Force
And the dimension of Force is MLT-2
The -2 is going to be in raise to power form....
Hope it helps....
Answer:
If the angular acceleration is a constant A, then this constant times the time will be equal to the angular velocity.
We know that after accelerating for 10 seconds, the angular velocity is 0.4 rad/s
Then:
A*10s = 0.4 rad/s
If we solve this for A we get:
A = (0.4 rad/s)/10s = 0.04 rad/s^2
This is the angular acceleartion.
Now we assume that the angular speed remains constant at 0.4 rad/s, and we know that the radius of the carousel is 20m, we want to find the linear velocity of the children.
We know that for an angular velocity W and for a radius R, the linear velocity is:
V = R*W
Then in this case the linear velocity is:
V = 20m*(0.4 s^(-1)) = 8 m/s