There are two torques t1 and t2 on the beam due to the weights, one torque t3 due to the weight of the beam, and one torque t4 due to the string.
You need to figure out t4 to know the tension in the string.
Since the whole thing is not moving t1 + t2 + t3 = t4.
torque t = r * F * sinФ = distance from axis of rotation * force * sin (∡ between r and F)
t1 =3.2 * 44g
t2 = 7 * 49g
t3 = 3.5 * 24g
t4 = t1 + t2 + t3 = 5570,118
The t4 also is given by:
t4 = r * T * sin Ф
r = 7
Ф = 32°
T: tension in the string
T = t4 / (r * sinФ)
T = t4 / (7 * sin(32°))
T = 1501,6 N
Efficiency is calculated through dividing the actual mechanical advantage by the hypothetical mechanical advantage:
- the actual mechanical advantage is 9J because that's how much work the light bulb doing
- the hypo. mechanical advantage is 100J. Ideally, in a perfect world, the light bulb can convert 100J input into 100J output, but do to resistance and other factors it is not possible.

change the decimal to a percentage:

the light bulb had 9% efficiency
The stress that can cause on the anticline , is the Compression
Answer:
(a) ε = 1373.8.
(b) The wingtip which is at higher potential.
Explanation:
(a) Finding the potential difference between the airplane wingtips.
Given the parameters
wingspan of the plane is = 18.0m
speed of the plane in north direction is = 70.0m/s
magnetic field of the earth is = 1.20μT
The potential difference is given as:
ε = Blv
where ε = potential difference of wingtips
B = magnetic field of earth
l = wingspan of airplane
v = speed of airplane
ε = 1.2 x 18.0 x 63.6
ε = 1373.8
(b) Which wingtip is at higher potential?
The wingtip which is at higher potential.
Answer: Shorter
Explanation: Shadow is formed when an light source is obstructed by an opaque object. The closer the source, shorter is the length of the shadow. In fact, when the source is exactly overhead, no shadow of the object is formed.
June 21 marks the Summer solstice which means the Sun passes directly overhead Tropic of cancer (23.5° N) at noon. March 21 marks the equinox which means sun passes directly overhead equator (0°).
Shadow length of an object at 42° Northern latitude will be shorter on June 21 because the Sun will be closer to this latitude as compared to March 21.