Hi,
The force that acts on hydraulic machine is heavy therefore the content must be something that cannot be compressed by that kind of force, the gas can easily be compressed while a liquid is nearly impossible to.
Choices 1, 2, and 4 . . . . . Yes
Choices 3 and 5 . . . . . No
The solution for the problem is:
Constant speed means Fnet = 0.
Let m = mass of wood block and Θ = angle of ramp; then if µk = 0.35 …
The computation would be:
Fnet = 0 = mg (sin Θ) - (µk) (mg) (cos Θ)
mg (sin Θ) = µk (mg) (cos Θ)
µk = tan Θ
Θ = arctan(µk)
= arctan (0.35)
≈ 19.3°
1N=1kg•m/s^2 so the answer is 3N
