Answer:
Part a)

Part b)
t = 12 s
Explanation:
Part a)
Tension in the rope at a distance x from the lower end is given as

so the speed of the wave at that position is given as

here we know that

now we have


Part b)
time taken by the wave to reach the top is given as




Answer:
A body will become positively charged when some electrons will come out from the body.Thus, positive charge is due to deficiency of electrons.
Answer:
E= 4.35*10^6 N/C
Explanation:
Let's find the area charge density of the plate
α= 6.9*10^-6/9*10^-2 = 7.7*10^-5C/m2
Now we can calculate the electric field just of the plate
E =α/2e =7.7*10^-5/2*8.85*10^-12 = 4.35*10^6 N/C
Answer:
80 amperes
Explanation:
Current in the circuit = ?
Voltage in the circuit = 160 Volts
Resistance = 2 Ω
Voltage = Current x Resistance
V = IR
160V = I x 2 Ω
I = 160V / 2 Ω
I = 80 Amperes
Therefore the current in the circuit is 80 amperes :)