Which of the following statements about the concept of solid friction is NOT true?
It always acts in the direction of motion
It causes wear and tear in car tyres
It depends on the nature of the surfaces in contact
It is independent of the area of the surfaces in contact.
It reduces the efficiency of the machine
Correct answer is A
No explanation has been provided for this answer.
15.0s
18.0s
22.5s
30.0s
45.0s
Correct answer is C
\(\frac{1}{16} = (\frac{1}{2})^n\)
\((\frac{1}{2})^4 = (\frac{1}{2})^n\)
\(n = 4\)
90 secs = 4 half lives
1 half life = \(\frac{90}{4}\) secs
= 22.5 secs
0.25ms-1
0.50ms-1
1.00ms-1
2.00ms-1
4.00ms-1
Correct answer is C
No explanation has been provided for this answer.
232
450
550
2750
11000
Correct answer is D
No explanation has been provided for this answer.
charges generated by friction in the tanker are conducted to the earth
chain vibrates in resonance with the tanker’s engine
heat generated by friction in the engine is conducted to the earth
petrol tanker is balanced on the road
tanker does not exceed a certain speed limit
Correct answer is A
No explanation has been provided for this answer.