Absolutely ! If you have two vectors with equal magnitudes and opposite
directions, then one of them is the negative of the other. Their correct
vector sum is zero, and that's exactly the magnitude of the resultant vector.
(Think of fifty football players pulling on each end of the rope in a tug-of-war.
Their forces are equal in magnitude but opposite in sign, and the flag that
hangs from the middle of the rope goes nowhere, because the resultant
force on it is zero.)
This gross, messy explanation is completely applicable when you're totaling up
the x-components or the y-components.
Mechanics is dealing with forces that are effecting some body, electrostatics is about electrical fields of not moving bodies, and quantum mechanics is dealing with quantum states of atoms.
Thermodynamics as the word say, is dealing with thermal energy that is moving (transferring from one body to another or even better from one medium to another).
Answer is C <span />
Answer:
the angular velocity of the carousel after the child has started running =
Explanation:
Given that
the mass of the child = m
The radius of the disc = R
moment of inertia I = 
change in time = 
By using the torque around the inertia ; we have:
T = I×∝
where
R×F = I × ∝
R×F = ∝
F = 
∝
∝ = 
( expression for angular angular acceleration)
The first equation of motion of rotating wheel can be expressed as :
where ;
∝ =
Then;
∴ the angular velocity of the carousel after the child has started running =
