Answer:
1. Distance travelled = 12 km.
2. Displacement = 8.6 km
Explanation:
From the question given above, the following data were obtained:
Distance 1 (d₁) = 7 km
Distance 2 (d₂) = 5 km
Total distance =?
Displacement =?
1. Determination of the distance travelled.
Distance 1 (d₁) = 7 km
Distance 2 (d₂) = 5 km
Total distance (dₜ) =?
dₜ = d₁ + d₂
dₜ = 7 + 5
dₜ = 12 km
2. Determination of the displacement.
In the attached photo, R is the displacement.
We can obtain the value of R by using the pythagoras theory as illustrated below:
R² = 7² + 5²
R² = 49 + 25
R² = 74
Take the square root of both side
R = √74
R = 8.6 km
The frequency of a simple harmonic oscillator such as a spring-mass system is given by
where
k is the spring constant
m is the mass attached to the spring.
Re-arranging the formula, we get:
and since we know the constant of the spring:
and the frequency of oscillation:
f=1.00 Hz
we can find the value of the mass attached to it:
The oldest way ... the way we've been using as long as we've been
walking on the Earth ... has been to use plants. Plants sit out in the
sun all day, capturing its energy and using it to make chemical compounds.
Then we come along, cut the plants down, and eat them. Our bodies
rip the chemical compounds apart and suck the solar energy out of them,
and then we use the energy to walk around, sing, and play video games.
Another way to capture the sun's energy is to build a dam across a creek
or a river, so that the water can't flow past it. You see, it was the sun's
energy that evaporated the water from the ocean and lifted it high into
the sky, giving it a lot of potential energy. The rain falls on high ground,
up in the mountains, so the water still has most of that potential energy
as it drizzles down the river to the ocean. If we catch it on its way, we
can use some of that potential energy to turn wheels, grind our grain,
turn our hydroelectric turbines to get electrical energy ... all kinds of jobs.
A modern, recent new way to capture some of the sun's energy is to use
photovoltaic cells. Those are the flat blue things that you see on roofs
everywhere. When the sun shines on them, they convert some of its
energy into electrical energy. We use some of what they produce, and
we store the rest in giant batteries, to use when the sun is not there.
Answer:
1) P₁ = -2 D, 2) P₂ = 6 D
Explanation:
for this exercise in geometric optics let's use the equation of the constructor
where f is the focal length, p and q are the distance to the object and the image, respectively
1) to see a distant object it must be at infinity (p = ∞)
q = f₁
2) for an object located at p = 25 cm
We can that in the two expressions we have the distance to the image, this is the distance where it can be seen clearly in general for a normal person is q = 50 cm
we substitute in the equations
1) f₁ = -50 cm
2)
= 0.06
f₂ = 16.67 cm
the expression for the power of the lenses is
P = 
where the focal length is in meters
1) P₁ = 1/0.50
P₁ = -2 D
2) P₂ = 1 /0.16667
P₂ = 6 D
