1st derivative gives velocity;
d r(t)/ dt = 2t i + 6 j + 4/t k
2nd derivative gives acceleration;
d^2 r(t)/ dt^2 = 2 i - 4/ t^2
Speed ;
Square root of (4 t^2 + 36 + 16/ t^2)
For a given time, like 2 seconds, t will be 2. And answer of speed will be scalar.
Electrical current will flow through a solid by the means of
electrons. The electrons in the solid
must be able to move from lower to higher electrical potential. The electric
current in certain solid electrolytes like ice is entirely composed of flowing
ions.
By definition we have to:
The electric current is the flow of electric charge due to the movement (usually of electrons) that a material travels.
Some properties are:
1) Electric conduction: The conductive materials have a large amount of free electrons, therefore, the passage of electricity is possible.
2) The current inside a circuit is directly proportional to the voltage and inversely proportional to the resistance of the circuit. This is what is known as ohm's law:

3) The current can be continuous or alternate.
Alternating current is the electric current in which the magnitude and direction vary cyclically.
The direct current is the flow of electric charges that does not change direction with time.
Answer:

Explanation:
<u>Motion in The Plane</u>
When an object is launched in free air with some angle respect to the horizontal, it describes a known parabolic path, comes to a maximum height and finally drops back to the ground level at a certain distance from the launching place.
The movement is split into two components: the horizontal component with constant speed and the vertical component with variable speed, modified by the acceleration of gravity. If we are given the values of
and
as the initial speed and angle, then we have




If we want to know the maximum height reached by the object, we find the value of t when
becomes zero, because the object stops going up and starts going down

Solving for t

Then we replace that value into y, to find the maximum height

Operating and simplifying

We have

The maximum height is


In the absence of air resistance , object fall with <u>same acceleration</u> .