Answer:
Length = 2.32 m
Explanation:
Let the length required be 'L'.
Given:
Resistance of the resistor (R) = 3.7 Ω
Radius of the rod (r) = 1.9 mm = 0.0019 m [1 mm = 0.001 m]
Resistivity of the material of rod (ρ) = 
First, let us find the area of the circular rod.
Area is given as:

Now, the resistance of the material is given by the formula:

Express this in terms of 'L'. This gives,

Now, plug in the given values and solve for length 'L'. This gives,

Therefore, the length of the material required to make a resistor of 3.7 Ω is 2.32 m.
The answer is Strontium(Sr)
Answer:
A drop in voltage occurs
Explanation:
When electric current flows through a conduct, there are three basic electrical effects that occur to the conductor;
1. A magnetic field is set up around the conductor,
A magnetic field is formed around a conductor when current flows through it which makes it acts like a magnet. Application is used in electric bells.
2. Heat is generated, and
The heating effect of current is due to the conversion of some of the electrical energy that passes through the conductor, into heat energy. Application of heat effect include electric iron, microwave oven, electric bulb, hair straightener etc.
H = I²Rt
3. A drop in voltage occurs
Voltage drop is as a result of current passing through the impedance offers by the conductor or circuit elements. When current passes through a conductor, the resistance offers opposition to the flow of the electric current according to Ohm's law.
Answer:
KE = 0.5 * m * v², where: m - mass, v - velocity.
Explanation:
In classical mechanics, kinetic energy (KE) is equal to half of an object's mass (1/2*m) multiplied by the velocity squared. For example, if a an object with a mass of 10 kg (m = 10 kg) is moving at a velocity of 5 meters per second (v = 5 m/s), the kinetic energy is equal to 125 Joules, or (1/2 * 10 kg) * 5 m/s 2.
Answer:
It takes about 88 seconds for the cannonball to reach its maximum height (ignoring air resistance).
Explanation: