How much work in J does the string do on the boy if the boy stands still?
<span>answer: None. The equation for work is W = force x distance. Since the boy isn't moving, the distance is zero. Anything times zero is zero </span>
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<span>How much work does the string do on the boy if the boy walks a horizontal distance of 11m away from the kite? </span>
<span>answer: might be a trick question since his direction away from the kite and his velocity weren't noted. Perhaps he just set the string down and walked away 11m from the kite. If he did this, it is the same as the first one...no work was done by the sting on the boy. </span>
<span>If he did walk backwards with no velocity indicated, and held the string and it stayed at 30 deg the answer would be: </span>
<span>4.5N + (boys negative acceleration * mass) = total force1 </span>
<span>work = total force1 x 11 meters </span>
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<span>How much work does the string do on the boy if the boy walks a horizontal distance of 11m toward the kite? </span>
<span>answer: same as above only reversed: </span>
<span>4.5N - (boys negative acceleration * mass) = total force2 </span>
<span>work = total force2 x 11 meters</span>
Answer:
vb = 22.13 m/s
So, the only thing that was measured here was the height of point A relative to point B. And the Law of Conservation of Energy was used.
Explanation:
In order to find the speed of roller coaster at Point B, we will use the law of conservation of Energy. In this situation, the law of conservation of energy states that:
K.E at A + P.E at A = K.E at B + P.E at B
(1/2)mvₐ² + mghₐ = (1/2)m(vb)² + mg(hb)
(1/2)vₙ² + ghₐ = (1/2)(vb)² + g(hb)
where,
vₙ = velocity of roller coaster at point a = 0 m/s
hₙ = height of roller coaster at point a = 25 m
g = 9.8 m/s²
vb = velocity of roller coaster at point B = ?
hb = Height of Point B = 0 m (since, point is the reference point)
Therefore,
(1/2)(0 m/s)² + (9.8 m/s²)(25 m) = (1/2)(vb)² + (9.8 m/s²)(0 m)
245 m²/s² * 2 = vb²
vb = √(490 m²/s²)
<u>vb = 22.13 m/s</u>
<u>So, the only thing that was measured here was the height of point A relative to point B. And the Law of Conservation of Energy was used.</u>
The right answer is B. hope this helps you :)
weightlessness is the complete or near complete absense of the sensation of weight.
when in freefall,the only force acting upon your body is the force of gravity a noun contact force.since the gravity cannot be felt without any other opposing forces,you would have no sensation of it.you would feel weightless when in a state of freefall.
