A) To obtain an inverted image of an object of same size a convex lens is used.
B)
In this question we have given
Distance between candle flame and screen=4
it means distance between candle flame and lens +distance between lens and screen =4m
u+v= 4m
u= v
therefore, 2u= 4m
or, u=-2m ( u is taken negative because it lies on left side of the lens)
and v=2m
we have to find the focal length of convex lens


Hence, Focal length of the lens is 1m
and lens should be placed at a distance of 2m from the flame
Incomplete question as the mass of baseball is missing.I have assume 0.2kg mass of baseball.So complete question is:
A baseball has mass 0.2 kg.If the velocity of a pitched ball has a magnitude of 44.5 m/sm/s and the batted ball's velocity is 55.5 m/sm/s in the opposite direction, find the magnitude of the change in momentum of the ball and of the impulse applied to it by the bat.
Answer:
ΔP=20 kg.m/s
Explanation:
Given data
Mass m=0.2 kg
Initial speed Vi=-44.5m/s
Final speed Vf=55.5 m/s
Required
Change in momentum ΔP
Solution
First we take the batted balls velocity as the final velocity and its direction is the positive direction and we take the pitched balls velocity as the initial velocity and so its direction will be negative direction.So we have:

Now we need to find the initial momentum
So

Substitute the given values

Now for final momentum

So the change in momentum is given as:
ΔP=P₂-P₁
![=[(11.1kg.m/s)-(-8.9kg.m/s)]\\=20kg.m/s](https://tex.z-dn.net/?f=%3D%5B%2811.1kg.m%2Fs%29-%28-8.9kg.m%2Fs%29%5D%5C%5C%3D20kg.m%2Fs)
ΔP=20 kg.m/s
Answer:
Explanation:Hooke's law states that " if the elastic limit of an elastic material is not exceeded, the extension,e is directly proportional to the applied force or load.
After the ball leaves the bat, the only forces on it are air resistance and gravity.