The question is at which point would a rollercoaster car have the least potential energy​
science

Abaseball picther can throw a ball at about 90 miles per hour, v = 40 m/s, on solid rock ground. we now put him into space. when he throws the ball, which weighs mb = 0.15 kg moves away from himat the same speed. how long does it take the ball thrown in space to travel the 30 meters to the batter? he weighs mp = 100kg

An ideal spring has a spring constant (force constant) of 2500 n/m, is stretched 4.0 cm, how much elastic potential energy does it possess? (a) 3j (b) 0.00j (c) 1j (d) 2j (e) 4j

Starting with only the balmer series light (visible light), how could we ensure that the solar panels generate a current that mark can use for his power station? a)by gradually increasing the brightness (amount) of light that we shine on it. b)by gradually increasing the frequency of the light we shine on it. c)by gradually increasing the wavelength of the light that we shine on it.