Answer:
The curl is 
Explanation:
Given the vector function

We can calculate the curl using the definition

Thus for the exercise we will have

So we will get

Working with the partial derivatives we get the curl

Answer:

Explanation:
For this case we can use the second law of Newton given by:

The friction force on this case is defined as :

Where N represent the normal force,
the kinetic friction coeffient and a the acceleration.
For this case we can assume that the only force is the friction force and we have:

Replacing the friction force we got:

We can cancel the mass and we have:

And now we can use the following kinematic formula in order to find the distance travelled:

Assuming the final velocity is 0 we can find the distance like this:

Answer:
7.04 m
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity = 0
s = Displacement on Earth = 1.2 m
a = Acceleration due to gravity on Moon = 1.67 m/s²
a = Acceleration due to gravity Earth= 9.81 m/s²
Accelration going up is considered as negetive
Initial Velocity of the ball

Assuming that the ball is thrown with the same velocity on the Moon, displacement of the ball is

The displacement of the ball on the moon is 7.04 m
Calculate the number of neutrons. Now you know that atomic number = number of protons, and mass number = number of protons + number of neutrons. To find the number of neutrons in an element, subtract the atomic number from the mass number.