Given:
distance from the projector lens to the image, di
projector lens focal length, f
distance from the transparency to the projector lens, do
thin lens equation: 1/f = 1/di + 1/do
do = 4 inches
di = 8 feet
convert feet to inches, for uniformity.
1 foot = 12 inches
8 feet * 12 inches/ft = 96 inches
1/f = 1/96 inches + 1/4 inches
Adding fractions, denominator must be the same.
1/f = (1/96 * 1/1) + (1/4 * 24/24)
1/f = 1/96 + 24/96
1/f = 25/96
to find the value of f, do cross multiplication
1*96 = f * 25
96 = 25f
96/25 = f
3.84 = f
The focal length of the project lens is 3.84 inches
PART a)
Before Drew throw Lily in forwards direction they both stays at rest
So initial speed of both of them is zero
So here we can say that initial momentum of both of them is zero
So total momentum of the system initially = ZERO
PART b)
Since there is no external force on the system of two
so there will be no change in the momentum of this system and it will remain same as initial momentum
So final momentum of both of them will be ZERO
PART c)
As we know that momentum of both will be zero always
so we have


in opposite direction
The displacement of the bird is 1.8 km...because displacement is the distanse of the object from mean position to the travelled position.....hope it helps
Work is the ability to cause life change??
Answer:
chemical to nuclear and radiant