Answer:
R = 2481 Ω
L= 1.67 H
Explanation:
(a) We have an inductor L which has an internal resistance of R. The inductor is connected to a battery with an emf of E = 12.0 V. So this circuit is equivalent to a simple RL circuit. It is given that the current is 4.86 mA at 0.725 ms after the connection is completed and is 6.45 mA after a long time. First we need to find the resistance of the inductor. The current flowing in an RL circuit is given by
i = E/R(1 -e^(-R/L)*t) (1)
at t --> ∞ the current is the maximum, that is,
i_max = E/R
solve for R and substitute to get,
R= E/i_max
R = 2481 Ω
(b) To find the inductance we will use i(t = 0.940 ms) = 4.86 mA, solve (1) for L as,
Rt/L = - In (1 - i/i_max
)
Or,
L = - Rt/In (1 - i/i_max
)
substitute with the givens to get,
L = -(2481 Si) (9.40 x 10-4 s)/ In (1 - 4.86/6.45
)
L= 1.67 H
<u><em>note :</em></u>
<u><em>error maybe in calculation but method is correct</em></u>
Answer:
a. E=1440KJ
b. E=360KJ
c. E=1.8 J
Explanation:
I have the power (Watts) is expressed as Energy (Joules) / Time (seconds), also I have to
so, for the lightbulb
Analogously, for the microwave
Now, I have to express the efficiency as Heat energy / power * 100 so
Done
Generally speaking, negative ions increase the flow of oxygen to the brain resulting in higher alertness, decreased drowsiness, and more mental energy.
To calculate the final velocity, we use Newton's first equation of linear motion:v=u+at
Where v is final velocity
u is initial velocity
a is the average acceleration
t is the time taken during acceleration.
Therefore,
v=0+2.5m/s²*6.00s
=15m/s
Decelerating from 15m/s;
v=15m/s+(-2m/s²×4.0s)
=3m/s
To get the distance it travelled, we use
v²=u²+2as
During acceleration, the distance travelled is calculated as below.
15²=0+2×2.5S
225=5S
S=45meters
During decellaration, displacement is calculated as below,
3²=15²+(2×4S)
9=225+8S
8S=216
S=27meters
Total displacement=45m+27m
=72 meters.
Answer:
Both the small car and the truck experience the same net force.
Explanation:
- Net force can be defined as the vector addition of all the forces that follow up on a particle or a body.
- It is a single force that changes the effect of the initial force on a particles motion.
- If in case the net force acting on a particular body is zero then it means that the object or the body is not moving or accelerating at all and is in a state of stability.