Answer:
19.95 J
Explanation:
The center of mass of the ladder is initially at a height of:

The center of mass of the ladder ends at a height of:
=L/2
So, the work done is equal to the change in potential energy which is:
W = PE = 
now 
therefore
W = [mgL/2]×[1 - sin(theta)]
W = [(7.30)(9.81)(2.50)/2]×[1-sin(51°)]
solving this we get
W = 19.95 J
The concave mirror is a spherical-shaped mirror that has an inner curved surface. Hence, option (4) is correct.
What is a concave mirror?
The concave mirrors are spherical-shaped mirrors that are painted on the outward surface. It is also known as the converging mirror, having the recessed inner reflecting surface.
- The concave mirrors are generally used for the purpose to focus the light. For that, they might have a reflecting surface, curved inwards, and the reflection of light is limited to the single focal point.
- The reflecting surface of the concave mirror has its vertex or midpoint lying farther away from the objects than the edges.
Thus, we can conclude that the surface of the concave mirror is curved inward. Hence, option (4) is correct.
Learn more about the concave mirror here:
brainly.com/question/13300307
Answer:
No acceleration.
Explanation:
If the forces are Balanced it means they are in equilibrium and there will be no net force, therefore the object will not accelerate and the velocity will remain constant.
Answer:
t = 36π seconds
Explanation:
For resolving this problem, we are going to consider a representative stadium of the United States. The Mercedes-Benz Stadium located in Atlanta, Georgia has an average radius of 90 m.
Then, its circumference measures:
L = 2πr
L = 2π(90)
L = 180π m
First, we estimate the wave's velocity: the average width of an person is 0.5 m, then the velocity is:
v = x/t
Where x: person's width
t: time
v = 0.5/0.1 = 5 m/s
The time required for the pulse to make one circuit around the stadium is:
t = x/v = 180π/5 = 36π seconds
Answer:
I dont really know much but i know that it swallow anything it comes across in space.