Answer:
The reflection and rectilinear propagation of light helps in the formation of shadows and also tells light doesn't penetrate opaque materials.
Answer:
The depth of focus achievable with those lenses is small.
Explanation:
A larger aperture makes it much harder to focus on more than one object. When using a telephoto lens (the ones the question is referring to), the depth of focus is very small. For example, using a telephoto lens to take a photo of a runner might get the runner in focus, but certainly not the track, or the audience behind them. If you look at photos, especially older photos, of Olympians in almost any sport you can see this.
Hope this helps!
Answer:
The pressure is 
Explanation:
From the question we are told that
The initial pressure is 
The temperature is 
Let the first volume be
Then the final volume will be 
Generally for a diatomic gas

Here r is the radius of the molecules which is mathematically represented as

Where
are the molar specific heat of a gas at constant pressure and the molar specific heat of a gas at constant volume with values

=> 
=> 
=> ![P_2 = [\frac{1}{2} ]^{\frac{7}{5} } * 11.2](https://tex.z-dn.net/?f=P_2%20%20%3D%20%20%5B%5Cfrac%7B1%7D%7B2%7D%20%5D%5E%7B%5Cfrac%7B7%7D%7B5%7D%20%7D%20%2A%2011.2)
=> 
Answer:
The driver hits the stationery dog because the applied force is less than required force
Explanation:
Kinetic energy will be given by
where m is the mass of the vehicle and v is the speed/velocity of the vehicle.
Substituting 800 Kg for m and 20 m/s for v we obtain

Frictional force by vehicle pads is given by
where d is the distance moved
Substituting 160000 for KE and 50 m for d we obtain

Therefore, the vehicle hits the dog since the required force is 3200N but the driver applied only 2000 N