Answer:
a) x = 0.200 m
b)E = 3.84*10^{-4} N/C 
Explanation:


DISTANCE BETWEEN BOTH POINT CHARGE = 0.5 m
by relation for electric field we have following relation

according to question E = 0
FROM FIGURE
x is the distance from left point charge where electric field is zero

solving for x we get

x = 0.200 m
b)electric field at half way mean x =0.25

E = 3.84*10^{-4} N/C 
 
        
                    
             
        
        
        
Answer:
Explanation:
Given
Initial speed 
distance traveled before coming to rest 
using equation of motion

where v=final velocity
u=initial velocity
a=acceleration
s=displacement

for 
using same relation we get

divide 1 and 2 we get


So a distance if 213.32 ft is required to stop the vehicle with 80 mph speed 
 
        
             
        
        
        
Answer:
The answer is B. 
Explanation:
They are in control of the experiment, they can change it the variables to better help the experiment.
 
        
                    
             
        
        
        
Answer: Macroscoptic Output
Explanation:
Answers to the rest:
1. B) macroscopic outputs.
2.A) a microscopic change creating a macroscopic output
3.B) Because the energy levels of the electrons in different metals are usually not the same, different metals usually emit different colors of visible light.
4.A) Heat is applied to a solid, causing its molecules to move quickly.
5.A) strontium, sodium, copper, potassium