The focal length of a magnifying glass is the distance between the focal point and optical centre of the magnifying glass.
<h3>Focal length</h3>
The focal length, f is the distance from a lens or mirror to the focal point, F.
This is the distance from a lens or mirror at which parallel light rays will meet for a converging lens or mirror or appear to diverge from for a diverging lens or mirror.
A magnifying glass is a converging lens which produces a enlarged, erect and virtual image when an object is placed between the focal point and optical centre.
A magnifying glass will bring to focus at a point sun rays which can cause the paper to catch fire if it is held in place for long.
This point at which the most concentrated ray of light is shining on the paper, is the focal point for that magnifying glass.
Therefore, the focal length of a magnifying glass is the distance between the focal point and optical centre of the magnifying glass.
Learn more about about focal length at: brainly.com/question/25779311
Answer:
9.81 × 10 = 98.1 meters
vertical displacement is s=1/2 at^2 + vt
initial vertical velocity is 0 so s=1/2 at^2
a in this instance is gravitational acceleration so 60m= 1/2 (9.81)t^2
solve for t, t = 3.497s. //I corrected this answer as just now I misread horizontal as vertical.
An elevator has 750,000 J when it is lived 500 meters in the air
Answer: Option D
<u>Explanation:</u>
The expression to find the potential energy completely on the basis of forces that on two objects. It can be written as
Where,
m – mass of object
Acceleration due to gravity = 
h = 500 meters
Force = 1500 Newton
As we know, according to Newton second law of motion, the force can be expressed in terms of mass and gravity (F= ma). So, the potential energy can be calculated as
Hence, an elevator has 750,000 J when it is lived 500 meters in the air.
Answer:
d=510.2m
t=10.2s
Explanation:
The formulas for accelerated motion are:
From them we can get 
.
We have:
And substitute:
We multiply both sides by 2a, and continue:
Being d the displacement 
, we have
For our exercise, we will write this as:
And taking upwards direction positive and imposing final velocity 0m/s (for maximum height), we have:
For the time we use:
The moon lacks an atmosphere compared to the Earth. Hope this helps!
