You legend, thanks so much!
But yeah with Q36, if anyone could provide an answer with motion theory that would be great since.(regardless thanks for the working/insight JI2015)
From my knowledge and a little bit of research, the question simply states that the length of the
same elastic band is no 0.4 metres with the
same mass hung on it. Last time, the length was .200, so it stretched 0.04 metres, however this time, only the length has doubled, thus the extension would double too. If the mass had been halved, then the extension would have been same as the last one (0.04 metres).
I couldn't exactly find the exact theory behind this, but, you can have a look at Hooke's Law (it's about springs, however, sometimes elasticity applies too).
I also wanted to extend a little on question 34 from JL2015's description (which is amazing
)
As the body is moving towards the spring (compressing it), the kinetic energy is being transformed into potential energy. However, it's not constant as it would require more energy to compress the spring even more. As the body slows down, the kinetic energy is slowly being lost into potential energy, thus, it can't be constant (so it can't be Answer A). Then you may think, about Answer C. It is wrong, due to the slope of the graph in Answer C, as it displays that the amount of kinetic energy being lost accelerates (if you look at the end part of it), however, it should slow down, as it compresses the spring.
Hope the explanation helps [too]