Convex Lenses are used to focus light and form a image. They are transparent.
They are one type of lenses. Different type of lenses are used to focus light differently. The basic lenses are concave and convex. Convex lenses converge light falling on it whereas concave lenses diverge light falling on it.
The answer is d, gravity is the only force acting on the object
Answer:
39.7 m
Explanation:
First, we conside only the last second of fall of the body. We can apply the following suvat equation:

where, taking downward as positive direction:
s = 23 m is the displacement of the body
t = 1 s is the time interval considered
is the acceleration
u is the velocity of the body at the beginning of that second
Solving for u, we find:

Now we can call this velocity that we found v,
v = 18 m/s
And we can now consider the first part of the fall, where we can apply the following suvat equation:

where
v = 18 m/s
u = 0 (the body falls from rest)
s' is the displacement of the body before the last second
Solving for s',

Therefore, the total heigth of the building is the sum of s and s':
h = s + s' = 23 m + 16.7 m = 39.7 m
Answer:
When the volume increases or when the temperature decreases
Explanation:
The ideal gas equation states that:

where
p is the gas pressure
V is the volume
n is the number of moles of gas
R is the gas constant
T is the gas temperature
Assuming that we have a fixed amount of gas, so n is constant, we can rewrite the equation as

which means the following:
- Pressure is inversely proportional to the volume: this means that the pressure decreases when the volume increases
- Pressure is directly proportional to the temperature: this means that the pressure decreases when the temperature decreases
Answer:
B. 17.15 watts
Explanation:
Given that
Time = 10 seconds
height = distance = 0.7 meters
weight of sack = mg = F = 245 newtons
Power = work done/ time taken
Where work done = force × distance
Substituting the given parameters into the formula
Work done = 245 newton × 0.7 meters
Work done = 171.5 J
Recall,
Power = work done/time
Power = 171.5 J ÷ 10
Power = 17.15 watts
Hence the power expended is B. 17.15 watts