25mph I hope this helps and sorry it took so long
Static charge is occurring
There are two types of equilibrium in mechanics.One is called static equilibrium and the other one is called dynamic equilibrium. In both the cases of mechanical equilibrium,the net force acting on the particle is zero.
A body is said to be in dynamic equilibrium if the net force acting on a moving body is zero.There will be no acceleration of the body.The body will continue its uniform motion without change in its direction and speed.
The body is said to be in static equilibrium if the net force acting on a body at rest is zero.As the net force is zero,the body will not undergo motion. It is due to the inertia of the body.
The two equilibrium are the direct consequences of Newton's first law which tells that a body will continue to be at state of rest or uniform motion along a straight line unless and until it is compelled by some external unbalanced force.Hence as long as net force on the body is zero,the body at rest will satisfy static equilibrium.
Out of the four options given in the question only third option is right which tells that a book that has no net force acting on it and sitting on a table is under static equilibrium. If the net force is not zero,the body can not be under static equilibrium.The book resting on a table imparts a force equal to its weight on the table and table in turn gives the normal reaction in vertically upward direction.The gravity pulls the book in vertically downward direction with a force equal to its weigh.Hence the net force is zero.So the table will be at rest.
If the net force is not zero,the body can not be under static equilibrium.
Hence option 3 is right.
Answer:
3.08m/s²
Explanation:
Given parameters:
Radius = 20m
Tangential velocity = 7.85m/s
Unknown:
Centripetal acceleration = ?
Solution:
Centripetal acceleration is the acceleration of a body along a circular path.
it is mathematically given as;
a = 
v is the tangential velocity
r is the radius
a = 
= 3.08m/s²
Answer:
Explanation:
Given:
height above the horizontal form where the ball is hit, 
angle of projectile above the horizontal, 
initial speed of the projectile, 
<u>Firstly we find the </u><u>vertical component of the initial velocity</u><u>:</u>
During the course of ascend in height of the ball when it reaches the maximum height then its vertical component of the velocity becomes zero.
So final vertical velocity during the course of ascend:
Using eq. of motion:
(-ve sign means that the direction of velocity is opposite to the direction of acceleration)
(from the height where it is thrown)
<u>Now we find the time taken to ascend to this height:</u>
<u>Time taken to descent the total height:</u>
- we've total height,
- during the course of descend its initial vertical velocity is zero because it is at the top height, so
<u>Now the total time taken by the ball to hit the ground:</u>
