Answer:
The focal length of the lens in ethyl alcohol is 41.07 cm.
Explanation:
Given that,
Refractive index of glass= 1.500
Refractive index of air= 1.000
Refractive index of ethyl alcohol = 1.360
Focal length = 11.5 cm
We need to calculate the focal length of the lens in ethyl alcohol
Using formula of focal length for glass air system

Using formula of focal length for glass ethyl alcohol system

Divided equation (II) by (I)

Where,
= refractive index of glass
= refractive index of air
= refractive index of ethyl
Put the value into the formula




Hence, The focal length of the lens in ethyl alcohol is 41.07 cm.
Stopped at the end of the tracks by a spg-damper system, as shown in fig. 1
Answer:
chicken
Explanation:
you like chicken and want to eat it
Answer:
0.423m
Explanation:
Conversion to metric unit
d = 4.8 cm = 0.048m
Let water density be 
Let gravitational acceleration g = 9.8 m/s2
Let x (m) be the length that the spring is stretched in equilibrium, x is also the length of the cylinder that is submerged in water since originally at a non-stretching position, the cylinder barely touches the water surface.
Now that the system is in equilibrium, the spring force and buoyancy force must equal to the gravity force of the cylinder. We have the following force equation:

Where
N is the spring force,
is the buoyancy force, which equals to the weight
of the water displaced by the submerged portion of the cylinder, which is the product of water density
, submerged volume
and gravitational constant g. W = mg is the weight of the metal cylinder.

The submerged volume would be the product of cross-section area and the submerged length x

Plug that into our force equation and we have


