Answer:
Option e) 320 s
Explanation:
Here, distance = 3.0 km = 3000 m
The velocity of boat when it is going upstream;
Upstream velocity = velocity of boat in still water - velocity of river flow
So, Upstream velocity 
So,Time to go upstream

The velocity of boat when it is going downstream;
Downstream velocity = velocity of boat in still water + velocity of river flow
So, Downstream velocity 
So,Time to go downstream

So, total time (t) = 
Option E is the correct answer.
Answer:
F = - 1,598 10⁻³ N
Explanation:
Electic strength is given by Coulomb's law
F = k q₁ q₂ / r²
Where k is the Coulomb constant that is worth 8.99 10⁸ N m²/C², q₁ and q₂ are the charges and r is the distance that separates the electric charges
In this case the charge of the two spheres is the same and of a different sign since when you remove the charge of a sphere that was initially neutral, it is left with that charge removed but of the opposite sign
q₁ = q₂ = 2.50 10¹³ electrons = 2.50 10¹³ 1.6 10⁻¹⁹
q₀ = 4.0 10⁻⁶ C
Let's calculate
F = - 8.99 10⁸ (4.0 10⁻⁶)² / 0.30²
F = - 1,598 10⁻³ N
Answer:
Explanation:
Deceleration of solid disk = g sin10/1 + k²/r² = g sin 10 / 1 + 1/2 = g sin 10 x 2/3
[ k is radius of gyration of disk which is equal to( 1/√2)x r ]
deceleration a = -1.1345 m/s²
v = u - at , t = u / a = 1.5 / 1.1345 = 1.322 s.
Answer:
t = 402 years
Explanation:
To find the number of year that electrons take in crossing the complete transmission line, you first calculate the drift speed of the electrons. Then, you use the following formula for the current in a wire:
(1)
n: number of mobile charge carrier per volume = 8.50*10^28 e/m^3
q: charge of the electron = 1.6*10^-19 C
vd: drift velocity of electron in the metal = ?
A: cross sectional area of the wire = π r^2 = π (0.02m/2)^2 = 3.1415*10^-4 m^2
I: current in the wire = 1110 A
You solve the equation (1) for vd:

Next, you calculate the time by using the information about the length of the line transmission:

hence, the electrons will take aproximately 402 years in crossing the line of transmission
Answer:
Explanation:
y = 16 sinπx/15 cos(96πt)
When t = 0
y = 16 sinπx/15
here πx/15 is phase of the point at x
if x = 13
Phase = 13π/15
if x = 16
Phase = 16π/15
Phase difference
= 16π/15 - 13π/15
= 3π/15
= π/5 radian .