Answer:
The acceleration of the ball is 
Explanation:
From the question we are told that
The maximum height the ball reachs is 
The horizontal component of the initial velocity of the ball is
The vertical component of the initial velocity of the ball is 
The vertically motion of the ball can be mathematically represented as

Here the final velocity at the maximum height is zero so 
Making the acceleration
the subject we have

substituting values


The negative sign shows that the direction of the acceleration is in the negative y-axis
Answer:
<h2>
36cm from the surface</h2>
Explanation:
Equation of refraction of a lens is expression according to the formula given below;

R is the radius of curvature of the convex refracting surface = 12cm
v is the image distance from the refracting surface
u is the object distance from the refracting surface
n₁ and n₂ are the refractive indices of air and the medium respectively
Given parameters
R = 12 cm
u =
(since light incident is parallel to the axis)
n₁ = 1
n₂ = 1.5
Required
<em>focus point of the light that is incident and parallel to the central axis (v)</em>
<em />
Substituting this values into the given formula we will have;

Cross multiply

Hence Light incident parallel to the central axis is focused at a point 36cm from the surface
Answer:
Well the reason that elephants have big ears in the first place is to cool off. They flap their ears and use them as fans.