Answer:
Gravity
Explanation:
When the ball is falling to the ground, there is only one force- gravity. In some cases, there may be air resistance, but that seems to be neglected here.
Normal force:
Cannot be included. Normal force is only applicable when object is on a surface, and it acts perpendicular to the surface. Since the ball is falling, there is no surface, and therefore no normal force. This question gives you unnecessary information, designed to trick you. Please remember when normal force is applicable.
Friction force:
Also only applicable when object is moving, and is on the table. Friction only applies when there is an applied force. There is no applied force when the ball is falling, so therefore no friction force.
Force of fall:
First of all, what is this? There is nothing called force of fall.
Gravity:
This is the only one that applies. Just draw a vector arrow from the bottom of the ball and label it mg (acceleration due to gravity).
Answer:
1- The acceleration of the object is larger in magnitude the smaller the radius of the circle.
Explanation:
The acceleration of an object in a circular path is
As can be seen from the equation, if the radius of the circle is decreases, the magnitude of the acceleration increases.
As for the direction of the acceleration, it is always towards the center, and it is always perpendicular to the direction of the velocity.
My Physics teacher keeps giving us way too much work to do at home.
Answer:
The speed of the electron is 
.
Explanation:
Given that,
The magnitude of electric field, 
The magnitude of magnetic field, B = 0.516 T
Both the magnetic and electric fields are acting on the moving electron. Then, the magnitude of electric field and magnetic field is balanced such that :
or
So, the speed of the electron is . Hence, this is the required solution.
