Complete question:
A 45-mH ideal inductor is connected in series with a 60-Ω resistor through an ideal 15-V DC power supply and an open switch. If the switch is closed at time t = 0 s, what is the current 7.0 ms later?
Answer:
The current in the circuit 7 ms later is 0.2499 A
Explanation:
Given;
Ideal inductor, L = 45-mH
Resistor, R = 60-Ω
Ideal voltage supply, V = 15-V
Initial current at t = 0 seconds:
I₀ = V/R
I₀ = 15/60 = 0.25 A
Time constant, is given as:
T = L/R
T = (45 x 10⁻³) / (60)
T = 7.5 x 10⁻⁴ s
Change in current with respect to time, is given as;

Current in the circuit after 7 ms later:
t = 7 ms = 7 x 10⁻³ s

Therefore, the current in the circuit 7 ms later is 0.2499 A
Answer:
Kidneys filter our blood,
Explanation:
Hope this helped :)
Answer:
1. 31,536,000 seconds
2. Car B traveled a longer distance
3. Volume of box = 0.235887 cubic meters
Explanation:
Q1. Age in seconds
1 year = 365 days
1 day = 24 hours
1 hour = 60 minutes
1 minute = 60 seconds
Therefore 1 year = 365 x 24 x 60 x 60 = 31,536,000 seconds
In scientific notation this would be 
Q2. Comparing km and miles
Given:
1 km = 1000m and 1 m = 3.3ft, I km = 1000 x 3.3 = 3300 ft.
Convert Car A distance of 25.7km to feet :
25.7 km. = 25. 7 x 3300 ft. = 84,810 ft.
For Car B that traveled 20 miles,
20 miles = 20 x 5280 = 105,600 ft.
Since 105,600 > 84,810, car B traveled a longer distance
Q3. Volume of wooden box
The wooden box is in the shape of a rectangular prism
It volume is L x W x H
Volume = 1.525 x 0.30 x 0.5156 = 0.235887 cubic meters
Answer:
An electric motor converts electrical energy into mechanical energy. The process is as follows:
D. When current flows through the motor, it powers electromagnets that are attracted and repelled by the poles of permanent magnets in the motor. The movement of the electromagnets turns a rod in the motor, which makes the mechanical energy available.