Answer:
please give me brainlist and follow
Explanation:
Formula for number of images formed by two plane mirrors incident at an angle θ is n = 360∘θ. If n is even, the number of images is n-1, if n is an odd number of images.
 
        
             
        
        
        
The mass of lead required to make a 1.00 cm3 fishing sinker is 11.3g.
What is mass?
Mass is a metric used in physics to express inertia, a fundamental characteristic of all matter. A mass of matter's resistance to altering its direction or speed in response to the application of a force is what it essentially is. The change that an applied force produces is smaller the more mass a body has.
Given :
Density of lead = 11.3 g/cm3
Volume of  sinker  =  1.00 cm3 
One of a substance's attributes is density, which is calculated by dividing the mass by the volume. Mathematically:
Density : Mass / volume
therefore after putting the values,
mass= 11.3g 
To learn more about density click on the link below:
brainly.com/question/18939565
#SPJ4
 
        
             
        
        
        
Answer: (B) There is complete destructive interference between the incoming and reflected waves
Explanation:
For example, if you pluck a guitar the waves will travel back and forth. They consist of nodes and anti-nodes. It is created, when the wave traveling to one side and bounces of the other end and comes back. As it travels to the other side, it is reflected thus, comes back. So standing waves occurs when there is interference. 
When the wave is produced, the points where the string is not moving are called nodes and where they are moving are called anti-nodes. The positions where nodes are produced, destructive interference occurs and where anti-nodes are produced, constructive interference occurs
 
        
                    
             
        
        
        
Answer:
Explanation:
The vehicle is experiencing a large force created by the concrete wall.
Equation
vf^2 = vi^2 + 2*a * d
Givens
vf = 0   The car eventually does stop.
vi = 72 km/hr * [ 1000 m/  km] * [1 hour / 3600 seconds]
vi = 20 meters / second
a = ?
m = 850 kg
Solution
vf^2 = vi^2 + 2a*d
0 = 20 m/s + 2* 2 *a
-20 m/s = 4a
-20/4 =   a
a = - 5 m/s^2   The minus sign tells you the vehicle is slowing down. It sure should be.
Force = m * a
F = - 850 * (-5)
F =  - 4250 N
The car provides a 4250 N force on it going east to west and a 4250 N force going from west to east provided by the concrete wall.