1. Amperes, is the SI unit (also a fundamental unit) responsible for current.
2.
Δq over Δt technically
Rearrange for Δq
I x Δt = Δq
1.5mA x 5 = Δq
Δq = 0.0075
Divide this by the fundamental charge "e"
Electrons: 0.0075 / 1.60 x 10^-19
Electrons: 4.6875 x 10^16 or 4.7 x 10^16
3. So we know that the end resistances will be equal so:
ρ = RA/L
ρL = RA
ρL/A = R
Now we can set up two equations one for the resistance of the aluminum bar and one for the copper: Where 1 represents aluminum and 2 represents copper

We are looking for L2 so we can isolate using algebra to get:

If you fill in those values you get 0.0205
or 2.05 cm
Answer:
g = 1.64m/s²
Explanation:
1.5m in 0.078s
V = 15 / 0.078
= 19.23m/s
Tension = mg
μ = 3.10 × 10⁻⁴
T = V²μ
mg = V²μ
g = V²μ / m
g = ((19.23)²(3.10 × 10⁻⁴)) / (0.070)
g = 1.64m/s²
Explanation:
Watts are defined as 1 Watt = 1 Joule per second (1W = 1 J/s)
which means that 1 kW = 1000 J/s. A Watt is the amount of energy (in Joules) that an electrical device (such as a light) is burning per second that it's running.
First satellite was Sputnik and it was a race then to send satellites!! Everyone starts experimenting how to launch.
first try was on a dog , Laika !! It was send to space as it is long after sputnik is placed in orbit !!
Now you know everyone knows rocket science and the most active are ISRO (India) and NASA (USA) !!