Answer:
2.5 cm
40 D
Explanation:
When the radius of curvature of a lens is divided by 2 we get the focal length of the lens.
Focal length is given by

The focal length of the lens is 2.5 cm
When we divide 1 by the focal length in the unit of meters we get the power of a lens
Power of a lens is given by

The power of the lens is 40 D
Answer:
The angular velocity is 15.37 rad/s
Solution:
As per the question:

Horizontal distance, x = 30.1 m
Distance of the ball from the rotation axis is its radius, R = 1.15 m
Now,
To calculate the angular velocity:
Linear velocity, v = 
v = 
v = 
v = 
Now,
The angular velocity can be calculated as:

Thus

Answer:
Seeking matter and energy resources to sustain life, organisms in an ecosystem interact with one another in complex feeding hierarchies of producers, consumers, and decomposers, which together represent a food web.
Answer:
24.2 s
29.2 m
Explanation:
First, convert each speed from km/h to m/s.
91.5 km/h = 25.42 m/s
77.5 km/h = 21.53 m/s
The speed of the cheetah relative to the gazelle is:
v = 25.42 m/s − 21.53 m/s
v = 3.89 m/s
So the time it takes for the cheetah to catch the gazelle is:
x = v t
94.2 m = (3.89 m/s) t
t = 24.2 s
If instead we want to find x so that t = 7.5 s, then:
x = v t
x = (3.89 m/s) (7.5 s)
x = 29.2 m