Answer:
The question is incomplete, the complete question is "A car drives on a circular road of radius R. The distance driven by the car is given by d(t)= at^3+bt [where a and b are constants, and t in seconds will give d in meters]. In terms of a, b, and R, and when t = 3 seconds, find an expression for the magnitudes of (i) the tangential acceleration aTAN, and (ii) the radial acceleration aRAD3"
answers:
a.
b. 
Explanation:
First let state the mathematical expression for the tangential acceleration and the radial acceleration.
a. tangential acceleration is express as

since the distance is expressed as

the derivative is the velocity, hence

hence when we take the drivative of the velocity we arrive at
b. the expression for the radial acceleration is expressed as

(a) The distance will be more than 2.0 meters.
In fact, you starts your fall after your friend has already fallen 2.0 meters. This means that your friend has already accelerated for a while, therefore his velocity will be greater than yours. But this statement will be actually true for the entire fall, since you has some delay, therefore when your friend will hit the water, the separation between you and him will be greater than the initial separation of 2.0 meters.
b) First of all we need to calculate the height of the bridge with respect to the water. We know that you take 1.6 s to fall down, therefore we can use the following equation:

We know that your friend will take 1.6 s to falls down. Instead, you start your jump after he has already fallen 2.0 m, therefore after a time given by the equation:

Using S=2.0 m,

So we know that you start your fall 0.64 s after your friend. Therefore, now we can find how much did you fall between the moment you started your fall (0.64 s) and the moment your friend hits the water (1.6 s). Using

we find

So, when your friend hits the water, you just covered 4.52 m, while he already covered 12.56 m. Therefore, the separation between you and your friend is more than 2 meters.
Answer: A positively charged ion/ cation
Explanation: When an atom loses all of its electrons, it becomes a positively charged ion. Also referred to as the cation, the object will have a shortage of electrons, leading to a positive charge. Keep in mind that an atom will become positive if it loses electrons, and will become negative if it gains electrons.
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Answer:
H = 27.35 m
Explanation:
From projectile motion, we know that;
h = (v_o)²/2g
Where;
v_o = 12 m/s
g = 9.8 m/s²
Thus;
h = 12²/(2 × 9.8)
h = 144/19.6
h = 7.35 m
Now, we are told that when the man is 20 m above the pillow, he lets go of
the rope.
Thus, greatest height reached by the man above the ground is;
H = 20 + h
H = = 20 + 7.35
H = 27.35 m