Well if the rock doesn't move, then there is no amount of work done. There is no work done on an object if a force is applied to the object but it DOES NOT change its position, in this case is the rock.
This is what I got:
Net force in the Y direction:
ΣFy = T1 - T2
F = ma
ma = T1 - T2
Isolate for T2
ma - T1 = -T2
Multiply by -1
T1 - ma = T2
100 - (3)(2) = T2
100 - 6 = T2
T2 = 94 N
Answer:
the weight of the ball is w = 51.94 N ( mass = 5.3 kg)
Explanation:
Following Newton's second law:
net force = mass * acceleration = weight/gravity * acceleration
then denoting 1 and 2 as the first and second lift
F₁ - w= w/g *a₁
F₂ -w = w/g *a₂ = w/g * 2.07a
dividing both equations
(F₂- w)/(F₁ -w)= 2.07
(F₂- w) = 2.07 * (F₁ -w)
1.07*w = 2.07*F₁ - F₂
w = (2.07*F₁ - F₂ )/ 1.07
replacing values
w = (2.07*61.1 N - 70.9 N )/ 1.07 = 51.94 N
then the weight of the ball is w = 51.94 N ( mass = 5.3 kg)
Answer:
I = 215.76 A
Explanation:
The direction of magnetic field produced by conductor 1 on the location of conductor 2 is towards left. Based on Right Hand Rule -1 and taking figure 21.3 as reference, the direction of force Fm due to magnetic field produced at C_2 is shown above. The force Fm balances the weight of conductor 2.
Fm = u_o*I^2*L/2*π*d
where I is the current in each rod, d = 0.0082 m is the distance 27rId
between each, L = 0.85 m is the length of each rod.
Fm = 4π*10^-7*I^2*1.1/2*π*0.0083
The mass of each rod is m = 0.0276 kg
F_m = mg
4π*10^-7*I^2*1.1/2*π*0.0083=0.0276*9.8
I = 215.76 A
note:
mathematical calculation maybe wrong or having little bit error but the method is perfectly fine