According to the Jefferson lab, "The scientific definition of work is: using a force to move an object a distance (when both the force and the motion of the object are in the same direction.)"
Answer:
The solution and the explanation are in the Explanation section.
Explanation:
According to the diagram that is in the attached image, the EFFORT force at point A and the load is at O point. The torque due to weight is:
TA = W * (a * cosθ)
The torque due to effort at C point is:
TC = E * (b * cosθ)
The net torque is equal to 0, we have:
Tnet = 0
W * (a * cosθ) - E * (b * cosθ) = 0

From the figure, you can observe that a/b < 1, thus E < W
Answer:
Speed is solved with time and distance but has no direction
Average velocity is solved with Δx/Δt and has a direction
Answer: 7200 m
Explanation: The solution is, first convert 15 minutes to seconds.
15 mins x 60 s / 1 min = 900 s
Use the formula for speed which is v= d/t then derive for d.
d = vt
= 8 m/s ( 900s)
= 7200 m
Answer:
Part a)

Part b)

Explanation:
Part a)
Level of sound = 75 dB
now we know that

here we know that

now we have


Part b)
Intensity of sound wave is given as

here we know that

so we have


now we know



now we have

