Explanation:
The resistance of a wire is given by :

Where
is the resistivity of the wire
l = initial length of the wire
A = initial area of cross section
If length and the area of cross section of the wire is doubled then new length is l' and A', l' = 2 l and A' = 2 A
So, new resistance of the wire is given by :


R' = R
So, the resistance of the wire remains the same on doubling the length and the area of wire.
Answer:
0.2286 m, 0.686 m and 1,143 m
therefore we see that there is respect even where the intensity is minimal
Explanation:
Destructive interference to the two speakers is described by the expression
Δr = (2n +1) λ/2
where r is the distance, λ the wavelength and n an integer indicating the order of the interference
let's locate the origin on the left speaker
let's find the wavelength with the equation
v = λ f
λ = v / f
we substitute
Δr = (2n + 1) v / 2f
let's calculate for difference values of n
Δr = (2n +1) 343/(2 750)
Δr = (2n + 1) 0.2286
we locate the different values for a minimum of interim
n Δr (m)
0 0.2286
1 0.686
2 1,143
therefore we see that there is respect even where the intensity is minimal
Answer:

Explanation:
The rocket-powered sled is accelerated to a speed of 444 m/s in 1.83 seconds.
We need to find the acceleration of the rocket. Initially it was at rest, u = 0
Acceleration = rate of change of velocity

So, the acceleration of the rocket is
.
A) We need to first determine the volume of the continent and then mass would be = Volume x density
Volume = 4.7 x 10^6 m x 4.7 x 10^6 m x 37 x 10^3m
= 817 x 10^15 cubic meter
Mass = V x density
= 817 x 10^15 cubic meter x 2720kg/m^3
= 2.2 x 10^21 Kg
B)
Kinetic Energy = ½mV²
= ½ x 2.2 x 10^21 Kg x ( 4.6cm/year. x 1m/100cm x 1yr/365.24day x 1day/24hr x 1hr/3600s)²
= 2340 J