The illustration shows a rollercoaster add indicates four different positions the car might be at as it moves along the track. If friction weren’t a factor and no energy was lost, at which point in the rollercoaster journey is its potential energy the greatest? Choices:

A: W
B: X
C: Y
D: Z

Please help!

Aray of light traveling parallel to the principal axis of a concave mirror will be reflected through the mirror's

Could someone . i have tried to solve myself but my calculation is off

3. a worker pushes a 30.5 kg polished stone along a polished table with a force on bonin a straight line for 5.20 s after starting from rest. there is no friction between thestone and the table. at the end of the table. the stone is hooked to a cable with a lengthof 62.0 cm to rotate it to a rough table to store until they can be picked up. the roughtable has a coefficient of static friction 0.702 with the polished stone. remember that 8= 9.80 m/s2a) what is the speed of the stone when it is hooked to the cable? b) what is the tension in the cable while the stone is rotating? (there is still nofriction)c) how much force is needed to make the stone begin sliding from rest on therough table? ius = 0.70262.0 cm30.5 kg20.5 kg6= 0