Answer:
A
Explanation:
There is a mechanical advantage in this system....
she only needed 100 N to lift 500 N
1:5 she lifted it 2 meters, so if there WAS NO friction, she would have to pull in 5 x 2 = 10 meters
but there IS friction so she must have pulled in MORE than 10 m
Answer:

Explanation:
When an electric charge is immersed in an electric field, it experiences a force given by the equation

where
q is the charge
E is the magnitude of the electric field
In this problem, we have:
is the charge on the small piece of lint
is the force experienced by the charge
Therefore, we can find the magnitude of the electric field by re-arranging the equation and solving for E:

The bowling ball will require more force to roll because it is more massive.
Answer:
W = 71J
Explanation:
Given force F = (5i+5j−1k)N
d = Δr
r1 = (−5,−3,−4)m
r2 = (2,5,0)m
Δr = r2 – r1 = (2-(-5), 5-(-3), 0-(-4))
Δr = (2+5, 5+3, 0+4) = (7i+ 8j +4k)m
W = F•d = (5i+5j−1k)•(7i+ 8j +4k)
W = 5×7 + 5×8 +-1×4 = 35 + 40 - 4
W = 71J