The car's final velocity is 11.6 m/s in the opposite direction.
Answer:

Explanation:
The force excerted by a magnetic field on a charged particle is given by the Lorentz force:

Lets consider the z-direction of our coordinate system the same direction of the magnetic field, that is:

Let us consider that the velocity of a given particle is:

Therefore, since k×k = 0

And since i, j , k are a rigth hand system:
i × j = k
j × k = i
k × i = j --> i × k= -j

Threfore, if the particle has charge q and velocity v = (vx,vy,vz), the magnetic force it will feel will be

The tiger's position at time <em>t</em> is given by
<em>x</em> (horizontal) = (4.5 m/s) <em>t</em>
<em>y</em> (vertical) = 7.5 m - 1/2 <em>gt</em> ²
Solve <em>y</em> = 0 for <em>t</em> to find the time it takes for the tiger to reach the ground :
0 = 7.5 m - 1/2 (9.8 m/s²) <em>t</em> ²
===> <em>t</em> = √(2 (7.5 m) / (9.8 m/s²)) ≈ 1.2 s
Evaluate <em>x</em> at this time :
<em>x</em> = (4.5 m/s) (1.2 s) ≈ 5.6 m
Here since both children and merry go round is our system and there is no torque acting on this system
So we will use angular momentum conservation in this

now here we have



Now when children come to the position of half radius
then we will have



now from above equation we have


Answer:
The car is decelerating and its acceleration is negative.
Explanation:
First thing to consider. The car traveling direction is not important to answer the question.
Second, there are two affirmations on each sentence. So, lets take definitions:
Deceleration: Reducing the acceleration, from one value to another. No matter if the acceleration for the moment is positive or negative.
Acceleration negative: the driver is applying a force to make speed=0, the sign of this force must negative in order for the car to stop, other way it will go faster. Acceleration is the change rate of speed, if the speed is going down, the total acceleration until cars stops must be negative.