Answer:
The magnitude of the acceleration is 1.2 × 10⁴ mi/h²
Explanation:
Hi there!
The acceleration is defined as the change in velocity in a time:
a = Δv / Δt
Where:
a = acceleration.
Δv = change in velocity  = final velocity - initial velocity.
Δt = elapsed time.
In this case: 
Initial velocity = 60 mi/h
final velocity = 50 mi/h
elapsed time = 3.0 s
Let´s convert the time unit into h:
3.0 s · 1 h /3600 s = 1/1200 h
Now, let´s calculate the acceleration:
a = Δv / Δt
a = (50 mi/h - 60 mi/h) / 1/1200 h
a = -1.2 × 10⁴ mi/h²
The magnitude of the acceleration is 1.2 × 10⁴ mi/h²
 
        
             
        
        
        
Answer:
Refracted rays travel through a boundary into a new medium.
Explanation:
Refracted rays travel through a boundary into a new medium. is only true for refraction. 
The angle of incidence is the same for angle of refraction, is not true for refraction. Refraction follows Snell's law, states that ratio of the sine of the angle of refraction and the sine of the angle of incidence is always constant and equivalent to the ratio of phase velocities of the two mediums it is passing through. 
Refracted rays change direction and go back to the original medium is false for refraction however, it is true for reflection. 
 
        
             
        
        
        
Answer: option d.  Explanation:
Explanation:1) The 
direction of the 
field lines inform about the 
sign of the charges.
The field lines <span>
extend from the positive charges to the negative charges, so you can conclude that the charge C is positve and both charge A and charge B are negative:
</span><span>
</span><span>
</span><span>Charge C: positive
</span><span>
</span><span>Charge A: negative
</span><span>
</span><span>Charge B: netative
</span>
2) The 
density of the lines (number of lines in a region) inform about the 
magnitude of the electric field.
Since the charges are at the same distance, the magnitude of the electric field informs directly about the magnitude of the force and that about the magnitude of the charges.
Since, there are the 
double of lines between C and B than between C and A, the magnitude of 
charge B is the double than the magnitud of charge A.
From the five options given (a throug e) the only that is consistent with that charges A and B have the same sign, that charge C has different sign, and that charge B is the double of charge A is:
 
 
        
             
        
        
        
Answer:
An electric motor converts electrical energy into mechanical energy. The process is as follows:
D. When current flows through the motor, it powers electromagnets that are attracted and repelled by the poles of permanent magnets in the motor. The movement of the electromagnets turns a rod in the motor, which makes the mechanical energy available.