Answer:
-6112.26 J
Explanation:
The initial kinetic energy,
is given by
} where m is the mass of a body and
is the initial velocity
The final kinetic energy,
is given by
where
is the final velocity
Change in kinetic energy,
is given by

Since the skater finally comes to rest, the final velocity is zero. Substituting 0 for
and 12.6 m/s for
and 77 Kg for m we obtain

From work energy theorem, work done by a force is equal to the change in kinetic energy hence for this case work done equals <u>-6112.26 J</u>
Answer:
the work converted to thermal energy is 40 J.
Explanation:
Given;
work done by the physicist,w = 100 J
height through which the book is raised, h = 0.2 m
efficiency of machine = 60% = 0.6
The useful work done by the machine is calculated as;
useful work = 0.6 x 100 = 60 J
The wasted energy = 100 J - 60 J
The wasted energy = 40 J
The wasted energy by the machine is possibly converted to thermal energy by the frictional part of the machine.
Therefore, the work converted to thermal energy is 40 J.
Answer:
8
Explanation:
(8√2)² = x² + x²
8² × √2² = 2x²
64 × 2 = 2x²
128 = 2x²
64 = x²
x = 8
give me brainliest please
Answer:
No collision or altered trajectory
Similar percentage of oxygen isotopes
Explanation:
Capture hypothesis states that the Earth captured the moon. This is highly unlikely as such interactions of this type of bodies leads to a collision or their trajectories are altered. The percentage of the oxygen isotopes such as 16O, 17O and 18O in the Moon's basalts are almost identical with Earth. While meteorites have different percentage of oxygen isotopes.
Currently the accepted hypothesis is the giant-impact hypothesis.
Answer:
58.9 N
Explanation:
The wood is buoyed up by the mass of the water is displaces
wood volume = .030 m^3 = 30 000 cm^3
mass of water displaced = 30 000 g = 30 kg
wood mass = 800 kg/m^3 * .030 m^3 = 24 kg
so tension in string = mg = ( 30 kg - 24 kg) * 9.81 m/s^2 = 58.9 N