Q1. The volume of 50g of a substance is 20cm3 . If the denstiy of water is 1 g cm3, will the substance float or sink in water ? justify your answer ?
Q2. Show that the energy of a vibrating pendulum is conserved ?
Q3. A ball is dropped from a heigh of 10m. If the energy of the ball reduces by 40% after striking the ground, how much high can the ball bounce back ?
1.volume of substance= 20 cm3
mass of substance= 50 g
density of substance = mass/volume
=50/20
= 2.5 g/cm3
density of water = 1 g/cm3
2.5 >1
density of substance > density of water
therefore the substance will sink in water.