Answer:
The moment arm is 0.6 m
Explanation:
Given that,
First force 
Second force 
Distance r = 0.2 m
We need to calculate the moment arm
Using formula of torque
So, Here,
We know that,
The torque is the product of the force and distance.
Put the value of torque in the equation
Where, 
=First force
=First force
=Second force
= distance
Put the value into the formula
Hence, The moment arm is 0.6 m
Answer:
C. The change of internal energy of a system is the sum of work and heat spent on it.
Explanation:
The law of conservation of Energy states that energy cannot be destroyed but can only be converted or transformed from one form to another. Therefore, the sum of the initial kinetic energy and potential energy is equal to the sum of the final kinetic energy and potential energy.
Mathematically, it is given by the formula;
Ki + Ui = Kf + Uf .......equation 1
Where;
Ki and Kf are the initial and final kinetic energy respectively.
Ui and Uf are the initial and final potential energy respectively.
The law of conservation of Energy is another way to describe the law of Thermodynamics. It states that the change of internal energy of a system is the sum of work and heat spent on it.
Mathematically, it is given by the formula;
ΔU = Q − W
Where;
ΔU represents the change in internal energy of a system.
Q represents the net heat transfer in and out of the system.
W represents the sum of work (net work) done on or by the system.
Answer:
Explanation:
We know that the frequency of the nth harmonic is given by 
, where 
is the fundamental harmonic. Since we have the values of two consecutive frequencies, we can do:
Which for our values means (we do not need the value of <em>n</em>, that is, which harmonics are the frequencies given):
Now we turn to the formula for the vibration frequency of a string (for the fundamental harmonic):
So the tension is:
Which for our values is:
Answer:
Removing some of the books reduced the mass of the box, and less force was needed to push it across the floor.
