Answer:
A. elements of the same kind with different numbers of neutrons
Explanation:
As we know that an atom is represented by

here we know that
z = atomic number
A = atomic number + number of neutrons
now if the number of neutrons in an atom is different but having same number atomic number then the combination of such group of atoms is known as isotopes.
So here we have

so above is the example of isotopes
Answer:
Resultant horizontal force = 143 N
Explanation:
Since the a gle is 30° northwest, then it means the resultant force will be horizontal and as such;
Resultant horizontal force = 165 * cos 30
Resultant horizontal force = 142.89
Approximating to a whole number gives;
Resultant horizontal force = 143 N
Answer:
He has a speed of 16.60m/s after 35.0 meters.
Explanation:
The final velocity can be determined by means of the equations for a Uniformly Accelerated Rectilinear Motion:
(1)
The acceleration can be found by means of Newton's second law:
Where
is the net force, m is the mass and a is the acceleration.
(2)
All the forces can be easily represented in a free body diagram, as it is shown below.
Forces in the x axis:
(3)
Forces in the y axis:
(4)
Solving for the forces in the x axis:

Where
and
:


Replacing in equation (2) it is gotten:






So the acceleration for the cyclist is
, now that the acceleration is known, equation (1) can be used:

However, since he was originally at rest its initial velocity will be zero (
).



He has a speed of 16.60m/s after 35.0 meters
Answer: The gravitational acceleration on planet X is 5 N/kg
On Earth (with the gravitational accelartion g_E) the mass of 2kg will correspond to

On planet X we are told the same measure is only 10N. Since there is a proportional relationship between g and F, we can calculate g_X:

i think so it is frequency