Acarnival merry-go-round has a large disk-shaped platform of mass 120 kg that can rotate about a center axle. a 60-kg student stands at rest at the edge of the platform 4.0 m from its center. the platform is also at rest. the student starts running clockwise around the edge of the platform and attains a speed of 2.0 m/s relative to the ground.
(a) determine the rotational velocity of the platform.
(b) determine the change of kinetic enrgy of the system consisting of the platform and the student.
(c) draw bar charts for these.

Magma  is composed of molten rock and is  stored  in the earth's crust. lava is  magma  that reaches the surface of our planet through a volcano vent.

Physical science b final exam bernoulli’smovepowercompound translucent the sun i was having such a pain for this searching every question so i hope i made someone happy

The figure is missing but we can answer anyway.the correct answer is "releasing the string". in fact, when the person is holding the bow and the arrow, the kinetic energy of the arrow is still zero (because the arrow is not moving). the moment the arrow is released, it acquires a velocity v, so its kinetic energy will become different from zero: where m is the mass of the arrow and v its velocity.  all the other options, instead, do not increase the kinetic energy of the system: -  pulling farther back on the string : this will just increase the elastic potential energy of the system-  holding the arrow higher: this will increase the gravitational potential energy of the system (which is given by u=mgh, where h is the height above the ground)-  decreasing the mass of the arrow: this will decrease the gravitational potential energy of the system (which is given by u=mgh, where m is the mass)

D=m/v m=d*vd=densitym=massv=volumed(ether)=0.71 gr/cm³=0.71 gr/ mlv=130 mlm=d*vm=0.71 gr/ml*(130 ml)=92.3 gm=92.3 g