Answer:
80mm or 8cm
Explanation:
According to the lens formula,
1/f = 1/u+1/v
If the object distance u = 4cm = 40mm
Object height = 1.5mm
Image height = 3mm
First, we need to get the image distance (v) using the magnification formula Magnification = image distance/object distance = Image height/object height
v/40=3/1.5
1.5v = 120
v = 120/1.5
v = 80mm
The image distance is 80mm
To get the focal length, we will substitute the image distance and the object distance in the mirror formula to have;
1/f = 1/40+1/-80
Note that the image formed by the lens is an upright image (virtual), therefore the image distance will be negative.
Also the focal length of the converging lens is positive. Our formula will become;
1/f = 1/40-1/80
1/f = 2-1/80
1/f = 1/80
f = 80mm
The focal length of the lens 80mm or 8cm
Answer:
Therefore, the gravitational zero points between two planetoids lie at a distance of 3000 m from the center of planetoid 1.
Explanation:
From Newton’s gravitation formula, the expression of the mass (M) of the planet of radius R is given as,
Let's take x to be the distance of the zero gravitational points from the center of the planetoid 1.
Thus, the distance of the zero gravitational points from the center of the planetoid 2 is (D-x).
At zero gravitational point, the gravitational force between the planets and the rocket must be equal.
Explanation:
speed of an object is the magnitude of the rate of change of its position with time or the magnitude of the change of its position per unit of time; it is thus a scalar quantity.
Answer:
h = 65.021 m
Explanation:
Given that,
Initial velocity of a baseball, u = 17 m/s
It lands 2.3 seconds later.
We need to find the height of the building. Let it is h. It can be calculated using second equation of motion as follows :
here, a = g
So, the building is 65.021 m tall.