Where will a feather fall faster? in air or in vacuum? Why?
In vacuum because in air, the upthrust of the air is greater than the weight of the feather however, in vacuum, since there is no upthrust it will fall faster.
Which is less dense? Salt water or fresh water?
Fresh water
If we place an empty plastic bottle in water, it will float. How can we make the bottle sink in water?
By increasing the mass of the bottle by filling it with water or by filling it with denser objects like coins or pebbles
What is the effect of upthrust?
The weight of the body reduces in a fluid because of the upthrust and weight acting in opposite directions
According to Archimedes principle, upthrust acting on an object = ______________________
weight of the fluid displaced by the object
If an object is neutrally buoyant in a liquid (i.e upthrust = weight), ................
It will neither float nor sink. It will float just below the surface of the liquid.
Consider a wooden block. Which liquid will exert more upthrust on it - mercury or water? Why?
Mercury because mercury is highly denser than water
Why does changing a clay ball into a clay boat allows it to float?
Because the average density reduces due to the volume of air in the boat
True or False: If two objects have the same size or colour, they will both float.
False. Flotation depends on the mass of the object and density of the fluid.
The more tightly packed the particles within a substance are, the more _________ it is.
denser