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 diameter of the piston of the players equals 55.136 cm.
Explanation:
from the principle of transmission of pressure in a hydraulic lift we have

Since the force in the question is the weight of the individuals thus upon putting the values in the above equation we get

Solving for
we get

The answer yr looking for would b true!
The rotational speed of the person is 0.4 rad/s.
<h3>
Rotational speed (rad/s)</h3>
The rotational speed of the person in radian per second is calculated as follows;
v = ωr
where;
- v is linear speed in m/s
- r is radius in meters
- ω is speed in rad/s
ω = v/r
ω = 2/5
ω = 0.4 rad/s
Thus, the rotational speed of the person is 0.4 rad/s.
Learn more about rotational speed here: brainly.com/question/6860269