Answer:
well I mean it would depend on where u live for this question that's the only reason I am confused.. I'm pretty sure it's A thi
Answer:
(a) 
(b) 
Explanation:
We will take ground level as origin and upward is positive direction
the givens are

Part (a)
To find the final velocity we use the kinematic equation
So

Part (b)
To find time of rock trip until it touches the ground we will use simple kinematic equation or simple motion equation

Notice that we substituted vf with negative sign because its direction is downwards
Answer:
In the case of an electric bulb, the electrical energy is converted to light and heat. The amount of electrical energy put into a bulb = the amount of light energy (desirable form) plus the heat energy that comes out of the bulb (undesirable form).
Explanation:
sana nakatulong)):
Answer:
The magnitude of the net electric field is 
Explanation:
Given that,
Charge density 
Charge density 
Distance 
Distance 
We need to calculate the magnitude of the net electric field
Using formula of electric field


Put the value into the formula


Hence, The magnitude of the net electric field is 
Its becuase weight and mass are different. Even if an object weighs more than another object it might not have more mass than the other object.