Answer:
2.73414 seconds
467622.66798 J
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
g = Acceleration due to gravity = 9.81 m/s² = a



or

The time taken is 2.73414 seconds
The potential energy is given by

The change in potential energy is 467622.66798 J
Answer:
619.8 N
Explanation:
The tension in the string provides the centripetal force that keeps the rock in circular motion, so we can write:

where
T is the tension
m is the mass of the rock
v is the speed
r is the radius of the circular path
At the beginning,
T = 50.4 N
v = 21.1 m/s
r = 2.51 m
So we can use the equation to find the mass of the rock:

Later, the radius of the string is decreased to
r' = 1.22 m
While the speed is increased to
v' = 51.6 m/s
Substituting these new data into the equation, we find the tension at which the string breaks:

Answer:
The VSEPR theory and how it predicts the shapes of molecules:
Explanation:
The Valence Shell Electron Pair Repulsion (VSEPR) theory is a model used in chemistry to predict the shapes of individual molecules by the number of electron pairs that they have in the center of the atom. This theory is also based on the notion that the electrons around the atom repel one another. The Valence electrons on the outermost layer of the molecule are the most important in defining the geometry as they are the first to interact with other atoms and will be involved in bonding.
Answer:
a. The moment of the 4 N force is 16 N·m clockwise
b. The moment of the 6 N force is 12 N·m anticlockwise
Explanation:
In the figure, we have;
The distance from the point 'O', to the 6 N force = 2 m
The position of the 6 N force relative to the point 'O' = To the left of 'O'
The distance from the point 'O', to the 4 N force = 4 m
The position of the 4 N force relative to the point 'O' = To the right of 'O'
a. The moment of a force about a point, M = The force, F × The perpendicular distance of the force from the point
a. The moment of the 4 N force = 4 N × 4 m = 16 N·m clockwise
b. The moment of the 6 N force = 6 N × 2 m = 12 N·m anticlockwise.
Answer:
The answer is C
Explanation:
Force is a vector quantity so it has both magnitude and direction. The question shows 20N act as magnitude and Southeast act as direction.