Light years are the distance light can travel in a full year. They are used because there are really big distances in the universe that are easier to measure with a really large form of measurement (light years).
Answer:
the maximum mass that can hang without sinking is 2.93 kg
Explanation:
Given: details:
sphere diameter d = 20 cm
so, radius r = 10 cm = 0.10 m
density of the Styrofoam sphere D = 300 kg/m3
sphere volume ![V = \frac{4}{3} \pi r^3](https://tex.z-dn.net/?f=V%20%3D%20%5Cfrac%7B4%7D%7B3%7D%20%5Cpi%20r%5E3)
![=\frac{4}{3} \pi 0.10^3](https://tex.z-dn.net/?f=%3D%5Cfrac%7B4%7D%7B3%7D%20%5Cpi%200.10%5E3)
=4.18*10^{-3} m^3
we know that
![Density = \frac{Mass}{Volume}](https://tex.z-dn.net/?f=Density%20%3D%20%5Cfrac%7BMass%7D%7BVolume%7D)
mass M = Density * Volume
= (300)(4.18*10^{-3} m3)
=1.25 kg
mass of the water displace = volume *density of water
= 4.18*10^{-3} m3 * 1000
= 4.18 kg
The difference between the mass of water and mass of styrofoam is the amount of mass that the sphere can support
=4.18 kg -1.25 kg
= 2.93 kg
<span> If electricity and magnetism can create motion, can the reverse be true? Can motion and magnetism create electricity?</span>
Answer : Celestial or azimuth - altitude
Explanation :
Celestial : The celestial coordinates that are analogous to longitude and latitude are called RA and Dec.
RA = Right Ascension
Dec = Declination
RA is the measured in unit of time and Dec is measured in degree.
The equatorial coordinate system is the projection of the latitude and longitude coordinate system on the celestial sphere.
Azimuth - altitude : Azimuth - altitude define the location of an object in the sky.
The altitude is the distance of an object appears to be above the horizon.
The Azimuth of the object is the angular distance along the horizon to the location of the object.
Answer:
The mass of the child + skateboard is 50 kg
Explanation:
In this problem, we can apply Newton's second law:
F = ma
where
F is the net force on a system
m is the mass of the system
a is the acceleration of the system
In this problem, our system is the child + the skateboard. The net force on them is
F = 75 N
and their acceleration is
![a=1.5 m/s^2](https://tex.z-dn.net/?f=a%3D1.5%20m%2Fs%5E2)
So we can re-arrange the equation above to find their combined mass:
![m=\frac{F}{a}=\frac{75}{1.5}=50 kg](https://tex.z-dn.net/?f=m%3D%5Cfrac%7BF%7D%7Ba%7D%3D%5Cfrac%7B75%7D%7B1.5%7D%3D50%20kg)