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:
The correct answer is
a) 1, 2, 3
Explanation:
In rolling down an inclined plane, the potential energy is Transferred to both linear and rotational kinetic energy thus
PE = KE or mgh = 1/2×m×v² + 1/2×I×ω²
The transformation equation fom potential to kinetic energy is =
m×g×h = 
= 
= 
=
Therefore the order is with increasing rotational kinetic energy hence
the first is the sphere 1 followed by the disc 2 then the hoop 3
the correct order is a, 1, 2, 3
if you multiply the mass of an object by the acceleration due to gravity, you will obtain the object's weight. mass is an intrinsic property of matter
looks like a good answer ...
Answer:
Explanation:
We can find the resistance of the wire by using Ohm's law:
where
V is the voltage applied
R is the resistance
I is the current
In this problem, we know I = 6 A and V = 68 V, so we can re-arrange the equation to find the resistance of the wire:
Answer:
1. B. The person and the Earth
2. This is because the energy gained by the person equals the energy lost by the earth,
Explanation:
1.
B. The person and the Earth
This is because the person and the earth both represent a system. A system consists of more than one item. A system consists of two or more items interacting with each other.
2. This is because, the energy of an isolated system is conserved according to the second law of thermodynamics which states that in an isolated system, energy can neither be created nor destroyed. So, there is an exchange of energy between the person and the Earth. So, the energy gained by the person at the new height equals the energy lost by the earth. And thus, the total energy of the system remains constant.
