Question

(1)write difference between physical and chemical changes?


(2)explain why ice at 0 ℃ is more effective in cooling than water at the same temperature ?

(3)what is emulsion,?

(4)A bullet of mass20g is horizontally fired with a velocity 150m/s from a pistol of mass 2kg .What is the recoil velocity of the pistol

or

A car accelerates uniformly from 18km/h in 5 second calculate

1)The acceleration
2)The distance covered by the car in that time ​

Answer 1

1. Refer above.

2. Ice is more effective in cooling than water at the same temperature because ice can absorb latent heat as well as the heat energy in order to attain room temperature. Water at 0 C can absorb heat energy only to attain the room temperature.

3. a fine dispersion of minute droplets of one liquid in another in which it is not soluble or miscible.

Hope this helps...

Answer 2

Explanation:

physical change are changes which affects the chemical changes of a substances but not the chemical composition.

chemical changes are changes of materials into new materials with different properties, and also changes in the chemical composition of the substance.