Since there is no friction between the ladder and the wall, there can be no vertical force component. That's the tricky part ;)
So to find the weight, divide the 100N <em>normal</em> force by earths gravitational acceleration, 9.8m/s^2

Then;
Draw an arrow at the base of the ladder pointing towards the wall with a value of 30N, to show the frictional force.
Answer:
a) 2.41 km
b) 38.8°
Questions c and d are illegible.
Explanation:
We can express the displacements as vectors with origin on the point he started (0, 0).
When he traveled south he moved to (-3, 0).
When he moved east he moved to (-3, x)
The magnitude of the total displacement is found with Pythagoras theorem:
d^2 = dx^2 + dy^2
Rearranging:
dy^2 = d^2 - dx^2


The angle of the displacement vector is:
cos(a) = dx/d
a = arccos(dx/d)
a = arccos(3/3.85) = 38.8°
Answer:
The average atomic mass is 79.91 amu.
Explanation:
Since
Atomic mass can be find by Multiplying the relative abundance of each isotope by its atomic mass, then add them together to get the atomic mass of the element.
so
Atomic mass = (0.5069)(78.92 amu) + (0.4931)(80.92 amu)
=79.91 amu
So the Atomic mass of the bromine is 79.91amu.
can i get the question so that i can answer your question