Answer:
The mass of the block is 1250g.
Explanation:
Given that the formula for density is ρ = mass/volume. Then you have to substitute the values into the formula :
Let density = 250,
Let volume = 5,
Serena Williams has an average serve speed of 47 m/s. Find the mass of the tennis ball if its kinetic energy is 65 J.
1 answer:
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Considering the Ohm's law, the resistance of the lightbulb is 144.58 Ω.
<h3>Definition of current</h3>The flow of electricity through an object, such as a wire, is known as current (I). Its unit of measure is amps (A). So the current is a measure of the speed at which the charge passes a given reference point in a specified direction.
<h3>Definition of voltage</h3>The driving force (electrical pressure) behind the flow of a current is known as voltage and is measured in volts (V) (voltage can also be referred to as the potential difference or electromotive force). That is, voltage is a measure of the work required to move a charge from one point to another.
<h3>Definition of resistance</h3>Resistance (R) is the difficulty that a circuit opposes to the flow of a current and it is measured in ohms (Ω).
<h3>Ohm's law</h3>Ohm's law establishes the relationship between current, voltage, and resistance in an electrical circuit.
This law establishes that the intensity of the current that passes through a circuit is directly proportional to the voltage of the same and inversely proportional to the resistance that it presents.
Mathematically, Ohm's law is expressed as:
Where:
- I is the current measured in amps (A).
- V the voltage measured in volts (V).
- R the resistance that is measured in ohms (Ω).
In this case, you know that the voltage between two points in a circuit is 120 V and there is a current of 0.83 A.
Replacing in the Ohm's Law:
Solving:
0.83 A× R= 120 V
<u><em>R= 144.58 Ω</em></u>
Finally, the resistance of the lightbulb is 144.58 Ω.
Learn more about Ohm's law:
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Given :
Vector A has a magnitude of 63 units and points west, while vector B has the same magnitude and points due south.
To Find :
The magnitude and direction of
a) A + B .
b) A - B.
Solution :
Let , direction in north is given by +j and east is given by +i .
So , and
Now , A + B is given by :
Direction of A+B is 45° north of west .
Also , for A-B :
Direction of A-B is 45° south of west .
( When two vector of same magnitude which are perpendicular to each other are added or subtracted the resultant is always 45° from each of them)
Hence , this is the required solution .