On a sunny day, the concrete at the side of the pool feels much hotter than the water even though both have received the same thermal energy from the sun. explain fully why the concrete is hotter? (2)

Ahanging spring stretches by 35.0 cm when an object of mass 450 g is hung on it at rest. in this situation, we define its position as x = 0. the object is pulled down an additional 18.0 cm and released from rest to oscillate without friction. what is its position x at a moment 84.4 s later? express your answer in cm.