We first calculate the friction on the sled using:
F = ma
a = 20 / 22
a = 0.91 m/s²
Now we use the formula:
2as = v² - u²
v = √(2as + u²)
v = √[2(0.91)(5.2) + 0]
v = 3.08 m/s
Answer:
R = 710.7N
L = 67.689 N
During gravity fall L = R = 0 N
Explanation:
So the acceleration that the elevator is acting on the woman (and the package) in order to result in a net acceleration of 0.15g is
g + 0.15g = 1.15g
The force R that the elevator exerts on her feet would be product of acceleration and total mass (Newton's 2nd law):
a(m + M) = 1.15g(57 + 6) = 1.15*9.81*63 = 710.7N
The force L that she exerts on the package would be:
am = 1.15g *6 = 1.15*9.81*6 = 67.689N
When the system is falling, all have a net acceleration of g. So the acceleration that the elevator exerts on the woman (and the package) is 0, and so are the forces L and R.
Each pulley reduces the extra effort compulsory to lift the
elephant (light and 100% efficiency). If the elephant "weighs" 27,800
N and the person can apply 700 N,
27,800 / 700 = 39.7 which is about 40 N.
The answer that offers a combined # of 40 pulleys is computed by:
40 / 2 = 20
Therefore the answer is 20 fixed and 20 moveable.
His displacement is 0 .hope this helps :)
2.7 m/s2 average acceleration of a northbound subway train