This is another time to look at Newton's 2nd law of motion:
Net Force = (mass) x (acceleration)
If the object is not moving, then its acceleration is certainly zero, and Newton's law looks like this:
Net Force = (mass) x (zero)
or Net Force = (zero) .
"Net Force = zero" means that if there ARE any forces acting on the object, then they add up to zero, and we call them "balanced" forces.
So the answer is '<em>yes</em>', and that's why.
Answer:
The SI units for energy is Joules.
<h3>Answer</h3>
(A) Resistance is directly related to length.
<h3>Explanation</h3>
Formula for resistance
R = p(length) / A
where R = resistance
p = resistivity(material of wire)
A = cross sectional area
So it can be seen that resistance depends upon 3 factors that are length of wire , resistivity of wire and the cross sectional area of the wire.
If two of the factors, resistivity and cross sectional area, are kept constant then the resistance is directly proportional to the length of wire.
<h3> R ∝ length</h3>
This means that the resistance of the wire increases with the increase in length of the wire and decreases with the decrease of length of the wire.
Answer:
A kilowatt (kW) is a unit of power.
Explanation:
The power of an object is given by :
Here,
E is the energy required
t is time
The SI unit of power is Watts and the SI unit of energy is Joule. the commercial unit of energy is kilowatt per hour.
Option (1) : A kilojoule (kJ) is a unit of power is incorrect.
Option (2) : A gigawatt (GW) is a unit of energy is incorrect.
Option (3) : A watt (W) is a unit of energy is incorrect.
Option (4) : A kilowatt x hour per year (kWh/yr) is a unit of energy is incorrect.
Option (4) : A kilowatt (kW) is a unit of power is correct.
Hence, the correct option is (d).
