<span>Astronomers are able to determine facts about the composition of these moons by examining the nature of light that is reflected from their surfacy using a method called spectroscopy. This process works because different materials tend to reflect light at different wavelengths So, by observing at which wavelengths a planetary body reflects light, astronomers are able to estimate its composition.</span>

8 0

3 years ago

You need to know the height of a tower, but darkness obscures the ceiling. You note that a pendulum extending from the ceiling a

Sonja [21]

Answer:

L=55.9m

Explanation:

The equation for the period of a simple pendulum is:

$T=2\pi\sqrt{\frac{L}{g}}$

In our case what we know is the period and the acceleration of gravity, and we need to know the length of the pendulum, so we can write:

$L=(\frac{T}{2\pi})^2g$

Which for our values is:

$L=(\frac{15s}{2\pi})^2(9.81m/s^2)=55.9m$

6 0

3 years ago

What is the farthest distance at which a typical "nearsighted" frog can see clearly in air?

Umnica [9.8K]

Answer: the correct option is D (17m).

Explanation: The farthest distance at which a typical "nearsighted" frog can see clearly in air is 17m.

7 0

3 years ago

A 2.00-kg ball is moving at 2.20 m/s toward the right. It collides elastically with a 4.00-kg ball that is initially at rest. 1)

loris [4]

Elastic collision is when kinetic energy before = kinetic energy after

Ek= 1/2mv^2

total before
Ek=1/2(2)(2.2^2) = 4.84 J

total after
Ek= 1/2(2+4)(v^2) = 3v^2

Before = after
4.84=3v^2 | divide by 3
121/75 = v^2 | square root both sides
v=1.27 m/s

7 0

3 years ago