Answer:
bo sure but I think its c or a
Lol what???? i don’t understand
Answer:
Explanation:
Given
Initial velocity of ball 
height of window 
Using Equation of motion

where u=initial velocity
t=time
a=acceleration
As ball is already is at a height of 20 m so



(b)highest point is obtained at v=0

where
v=final velocity
u=initial velocity
a=acceleration
s=displacement



Highest Point will be 
(c)Time taken when the ball hit the ground i.e. at Y=0


impact velocity 
Answer:
Convection is equal to the conduction plus fluid flow.
Explanation:
Convection is a mode of heat transfer that requires the movement of the molecules of the medium from one point to another. It takes place majorly in fluids (liquids and gases). While conduction is a process by which heat is transfered by the vibtation of molecules of a medium at their possitions, thereby colliding with other neighbouring molecules to transmit heat.
Before convection could occur, there must be conduction of heat by the molecules of the medium which causes their motion. According to the kinetic molecular theory, any molecule of the medium close to the source of heat conducts heat, becomes less dense and thus moves so that its initial position would be occupied by another denser molecule. This continous process generate convection or convectional current. Therefore, convection is as a result of conduction and fluid flow because a molecule must first conduct heat before it moves.
Answer:
Here is the complete question.
If the magnitude of a positive charge is tripled, what is the ratio of the original value of the electric field at a point to the new value of the electric field at that same point.
a) 1:2
b) 1:3
c)1:6
d)1:9
b) 1:3 is the correct option.
Explanation: