Answer:
Because the mechanical advantage of the machine is affected by friction and weight but velocity ratio is not. So, mechanical advantage is less than velocity rate. Thus, the machine's efficiency is less than 100% and can't be a perfect machine
Answer:
We know there's two forces acting on a book while it sits on a table:the force of gravity pulling it down, and the normal force of the table acting upward on the book. The book isn't accelerating while it sits there. That's because the weight of the book is being counteracted by the normal force of the table.
Explanation:
There are two forces acting upon the book. One force - the Earth's gravitational pull - exerts a downward force. The other force - the push of the table on the book (sometimes referred to as a normal force) - pushes upward on the book.
Answer:
refractive index for water,glass,diamond are 0.752m, 0.667m, 0.413m respectively
Explanation:
refractive index (n) = 
velocity =
The time for travel is kept constant for all mediums.
refractive index (n) = 
distance in medium = 
For water, n= 1.33
For glass, n=1.5
For diamond, n= 2.42
Answer:
100,800 Jkg
The heat that is used to change the state of a mater is called latent heat.
In this case it is converting ice to water and it is called latent heat of fusion.
It is given by:
Heat = mc
where m is the mass of ice and l is the specific latent heat of fusion of ice.
l = 0.336 MJ
Heat = 0.3 × 0.336 MJ
= 0.3 × 0.336 × 10⁶
= 100,800 Jkg
It Is False. Liquid will not expand to fill it's container, while gas will.
