The equivalent resistance of several devices connected in parallel is given by
where
are the resistances of the various devices. We can see that every time we add a new device in parallel, the term
increases, therefore the equivalent resistance of the circuit
decreases.
But Ohm's law:
tells us that if the equivalent resistance decreases, the total current in the circuit increases. The power dissipated through the circuit (and so, the heat produced) depends on the square of the current:
therefore if there are too many devices connected in parallel, this can be a problem because there could be too much power dissipated (and too much heat) through the circuit.
Answer:
Momentum is always conserved, and kinetic energy may be conserved.
Explanation:
For an object moving on a horizontal, frictionless surface which makes a glancing collision with another object initially at rest on the surface, the type of collision experienced by this objects can either be elastic or an inelastic collision depending on whether the object sticks together after collision or separates and move with a common velocity after collision.
If the body separates and move with a common velocity after collision, the collision is elastic but if they sticks together after collision, the collision is inelastic.
Either ways the momentum of the bodies are always conserved since they will always move with a common velocity after collision but their kinetic energy may or may not be conserved after collision, it all depends whether they separates or stick together after collision and since we are not told in question whether or not they separate, we can conclude that their kinetic energy "may" be conserved.
Answer:
N = 3.54 * 10²³ atoms
Explanation:
The formula to apply here is the idea gas law;
PV = nRT where ;
P= pressure of the gas= 1.013 * 10⁵ Pa
V= volume of the gas = 4/3 * 3.14 *0.15³= 0.01414 m³
n= amount of a substance = ?
R= ideal gas constant= 8.314
T= temperature= 293 K
Applying the values to the formula;
PV = nRT
1.013 * 10⁵ * 0.01414 = n * 8.314*293
n= 1.013 * 10⁵ * 0.01414 / 8.314*293
n= 0.588 moles
1 mole = 6.022 * 10²⁷ atoms/ mole
0.588 moles = 0.588 * 6.022 * 10²⁷
N = 3.54 * 10²³ atoms
Answer:
limited liability, limitation in expansion, risk bearing, problem of continuity,
Answer:
- 5436 J
Explanation:
mass of car, m = 120 kg
radius of loop, r = 12 m
velocity at the bottom (A) = Va = 25 m/s
Velocity at the top(B) = Vb = 8 m/s
Vertical distance from A to B = diameter of loop, h = 2 x 12 = 24 m
by use of Work energy theorem
Work done by all the forces = change in kinetic energy of the body
Work done by the force + Work done by the friction = Kinetic energy at B - kinetic energy at A
- m x g x h + Work done by friction = 0.5 x 120 x (Vb^2 - Va^2)
- 120 x 9.8 x 24 + Work done by friction = 60 x (64 - 625)
- 28224 + Work done by friction = - 33660
Work done by friction = -33660 + 28224 = - 5436 J
