10

It is more difficult to walk on ice than on a concrete road because

 A) there is very little friction between the ice and feet pressing it B) ice is soft when compared to concrete C) there is more friction between the ice and feer D) None of these

Answer:   A) there is very little friction between the ice and feet pressing it

Explanation:

It is the friction between the feet and the ground that helps us to walk. Without this friction we would slip and fall

Subject: Physics

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• Related Questions

On the Kelvin scale ,the melting point of ice is

 A) 373K B) 100K C) 273K D) 0 K

Explanation:

Subject: Physics

1

Water has maximum density at............

 A) 0 C B) -15 C C) 4 C D) 15 C

Explanation:

Subject: Physics

0

Fish and other aquatic creatures canlive inside a deep frozen pond because

 A) fish are cold-blooded animals B) ice is a bad conductor of heat C) there will always be water just beneath the ice level D) they can adapt themselves to live in ice

Answer & Explanation Answer: C) there will always be water just beneath the ice level

Explanation:

Water has maximum density at $\inline \fn_jvn 4^{0}C$. So at this temperature it sinks down to bottom and stays here. If it cools further, it will become less dense and move up. So while the upper layers can cool enough to form ice, the bottom layers remain as water at $\inline \fn_jvn 4^{0}C$$\inline \fn_jvn \therefore$ (C) is correct.

Subject: Physics

11

At what temperature do the Fahrenheit and celcius scales give the same reading?

 A) 212 degrees B) 32 degreees C) -40 degreees D) 0 degreees

Explanation:

$\inline \fn_jvn F=C\times \frac{9}{5}+32$ We want the temperaature when F=C. So substituting C For F, we have C = $\inline \fn_jvn F=C\times \frac{9}{5}+32$

$\inline \fn_jvn \therefore$ C = -40. Thus when C = -40, we have C = F i.e, $\inline \fn_jvn -40^{0}F$

$\inline \fn_jvn \therefore$ (C) is coorrect. i.e,$\inline \fn_jvn -40^{0}C=-40^{0}F$

Subject: Physics

12

Pieces of camphor placed on water move about rapidly. This is because of

 A) diffusion B) viscosity C) surface tension D) capillarity