Answer:
The combined magnetic force of the magnetized wire coil and iron bar makes an electromagnet very strong. In fact, electromagnets are the strongest magnets made. An electromagnet is stronger if there are more turns in the coil of wire or there is more current flowing through it.
 
        
             
        
        
        
Answer:
100 Degrees is boiling point.
Explanation:
 
        
             
        
        
        
Answer:
The particle’s velocity is -16.9 m/s.
Explanation:
Given that,
Initial velocity of particle in negative x direction= 4.91 m/s
Time = 12.9 s
Final velocity of particle in positive x direction= 7.12 m/s
Before 12.4 sec,
Velocity of particle in negative x direction= 5.32 m/s
We need to calculate the acceleration
Using equation of motion


Where, v = final velocity
u = initial velocity
t = time
Put the value into the equation


We need to calculate the initial speed of the particle
Using equation of motion again


Put the value into the formula


Hence, The particle’s velocity is -16.9 m/s.
 
        
             
        
        
        
Sure.  The acceleration may be decreasing, but as long as it stays 
in the same direction as the velocity, the velocity increases.
I think you meant to ask whether the body can have increasing velocity 
with negative acceleration.  That answer isn't simple either.
If the body's velocity is in the positive direction, then positive acceleration 
means speeding up, and negative acceleration means slowing down.
BUT ... If the body's velocity is in the negative direction, then positive
acceleration means slowing down, and negative acceleration means 
speeding up.
I know that's confusing.  
-- Take a piece of scratch paper, write a 'plus' sign at one edge and 
a 'minus' sign at the other edge.  Those are the definitions of which 
direction is positive and which direction is negative.  
-- Then sketch some cars ... one traveling in the positive direction, and 
one driving in the negative direction.  Those are the directions of the
velocities.
-- Now, one car at a time:
. . . . . first push on the back of the car, in the direction it's moving;. 
. . . . . then push on the front of the car, against its motion.
Each push causes the car to accelerate in the direction of the push.
When you see it on paper, all the positive and negative velocities 
and accelerations will come clear for you.