Observe that the given vector field is a gradient field:
Let
, so that



Integrating the first equation with respect to
, we get

Differentiating this with respect to
gives

Now differentiating
with respect to
gives

Putting everything together, we find a scalar potential function whose gradient is
,

It follows that the curl of
is 0 (i.e. the zero vector).
Answer:
option D
Explanation:
given,

increase the intensity by factor of 9
I₁ = I₀
I₂ = 9 I₀
now,




A₂ = 3 A₁
hence, amplitude increase with the factor of 3
so, the correct answer is option D
Answer:
Explanation:
If the work done on the cart is NET work
Then the work will result in an increase in kinetic energy
KE₀ + W = KE₁
½mv₀² + W = ½mv₁²
½(0.80)(0.61²) + 0.91 = ½(0.80)v₁²
v₁ = 1.626991...
v₁ = 1.6 m/s
Answer:
V = f λ speed of wave in terms of frequency and wavelength
t = S / V time for wave to travel a distance S
t = 91.4 m / 344.5 m/s = .265 sec time to travel 91.4 m
Average speed = (total distance covered) / (time to cover the distance)
Total distance = (77km + 66km) = 143 kilometers
Time to cover the distance = 2 hours
Average speed = (143 km) / (2 hours) = 71.5 km per hour