A fire can be made by rubbing two objects together such as rubbing two pieces of rock having rough surfaces. Which of the following statements explain why a fire can be made by rubbing two objects together?
(i) Friction slows down moving objects.
(ii) Fire gives out heat and light energy.
(iii) Friction produces heat.
(iv) Fire has no mass.
A(ii) only
B(iii) only
C(i), (ii) and (iii) only
D(ii) and (iv) only
incorrect answer
Ans 3:
Class : Class 8
On rubbing two sticks together, friction produces heat and this leads to warming until the ignition point of the substance, when it catches fire. As per the options, onrubbing two sticks, *FIRE*produces heat and light and this *PRODUCES FIRE*.
Ans 7:
Class : Class 7
the answer is B because fire is caused due to friction not because it gives ot heat and light energy. Sof , could you please clear my doubt
Ans 10:
Class : Class 7
I think the question is talking about friction so look for the points which are related to both heat and friction