Answer:
a) Yes because spiderman isn’t part of the system (the train), so he exerts an external force on the system, causing it to slow. The sign is negative because the train is slowing negative.
b) The train was initially moving, so it had kinetic energy, the energy of movement. There isn’t the same amount anymore because spiderman did work onto the train. Work is defined by the change of kinetic energy of the system, so the train didn’t have the same amount of that type of energy at the end.
I hope this helps! :)
Answer:
Tangential speed = R * w where w is the angular speed
For a wheel v = .114 m * 6.53 / sec = .744 m/s
Note that this is the tangential speed - If the wheel were moving at speed V then as viewed from the ground you have
top V + v
bottom V - v
That is the wheel also has speed due to the speed of the axle (axis of rotation)
<span>1078 kgm / s would be the answer I hope this helps!!!</span>
