The correct answer is:
<span>B.) At terminal velocity there is no net force
In fact, when the parachutist reaches the terminal velocity, his velocity does not change any more. It means that the acceleration acting on the parachutist is zero, and for Newton's second law, this means the net force acting on him is zero:
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<span>because the acceleration is zero: a=0.
This also means that the two relevant forces acting on the parachutist (gravity, downward, and air resistance, upward) are balanced to produce a net force equal to zero.</span>
Answer:
2.7
Explanation:
The following data were obtained from the question:
Mass (m) of box = 100 Kg
Length (L) of ramp = 4 m
Height (H) of ramp = 1.5 m
Mechanical advantage (MA) of ramp =?
Mechanical advantage of a ramp is simply defined as the ratio of the length of the ramp to the height of the ramp. Mathematically, it is given by:
Mechanical Advantage = Lenght / height
MA= L/H
With the above formula, we can obtain the mechanical advantage of the ramp as follow:
Length (L) of ramp = 4 m
Height (H) of ramp = 1.5 m
Mechanical advantage (MA) of ramp =?
MA = 4/1.5
MA = 2.7
Therefore, the mechanical advantage of the ramp is 2.7
<span>h ( t) = h(1 sec) = -16t^2 + 541
so h (2 sec) = -16*(2)^2 + 541 = -64 + 541 = <span>477 ft
Therefore, </span></span>the height of the rock after 2 seconds is 477 feet.
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