C
Unbalanced causes something to move because the net force is greater than zero
Answer:

Explanation:
<u>Average Density
</u>
The density of an object of mass m and volume V is

If we know the density and the volume occupied by the object, the mass can be computed as

The tank can hold 20 L of gasoline when full. Converting to cubic meters

That's the volume of the gasoline it contains. Knowing the density of the gasoline, we get the mass of gasoline.

To know the total mass of both, we add the 2.5 kg of the tank

The volume of the tank is computed solving for V


The total volume is

The average density is


Since rope is parallel to the inclined plane so here we can say that net force parallel to the person which is pulling upwards must counterbalance the component of weight of the person.
Now here we will do the components of the weight of the person
given that weight of the person = 500 N
now its components are


now here as we can say that one of the component is balanced here by the normal force perpendicular to plane
while the other component of the weight is balanced by the force applied on the rope
So here the force applied on the rope will be given as


so it apply 300 N force along the inclined plane
Answer:
Explanation:
ignoring air resistance, the kinetic energy at water impact will equal the potential energy converted
½mv² = mgh
v = √(2gh)
v = √(2(9.81)2.1) = 6.4188... m/s
after impact, an impulse will result in a change of momentum.
There is a downward impulse due to gravity equal to the weight of the stone and an upward average force due to water resistance and buoyancy force.
FΔt = mΔv
(F - mg)Δt = m(vf - vi)
(F - mg) = m(vf - vi)/Δt
F = m(vf - vi)/Δt + mg
F = m((vf - vi)/Δt + g)
F = 1.05(((½(-6.4188) - -6.4188)/ 1.83) + 9.81)
F = 12.14198...
F = 12.1 N