Answer:

Explanation:
As per given figure let say the tip of the shadow is at distance "x" from the base of the lamp
so here we have

so we have


now we have



Answer:
v = 60 m/s
Explanation:
It is given that,
A wave is represented by the equation :
![y=0.2\sin [0.4\pi (x-60)t]](https://tex.z-dn.net/?f=y%3D0.2%5Csin%20%5B0.4%5Cpi%20%28x-60%29t%5D)
We need to find the velocity of the wave
The general equation of a wave is given by :
....(1)
Equation (1) can be written as :
...(2)
If we compare equation (1) and (2) we get :


The velocity of a wave is given by :

So, the velocity of the wave is 60 m/s.
Answer:
Before the front of the vehicle enters the intersection.
Explanation:
When stopping at a stop sign where there is no crosswalk or stop line, a driver should stop his/her vehicle before the front of the vehicle enters the intersection.
The front part of the vehicle comes in contact initially. On the other hand, the back part comes after that.
Hence, the correct option is (b).
Answer:
Density is equal to mass divided by volume.
Explanation:
Density = mass / volume
or
p=m/v