Around 80 percent of the mass of the universe is made up material known as "Dark matter". It does not emit light or energy but the influence of it can be detected or observed gravitationally. Motions of stars and galaxy tell us how much mater there is, but somehow the speed of rotation of galaxy does not add up to its mass alone, there is a certain amount of matter really not accounted for. Dark matter maybe made up of non-baryonic matter, or perhaps what scientist called the WIMPS or (weakly interacting massive particles.)
Answer:
Difference in temperature
Contact between the bodies
The law of Ohm defines the relationship in an electrical circuit between voltage, current and resistance: I = v / r. The current is directly proportional to the voltage and the resistance is inversely proportional.
The Canadian Shield<span>, also called the Laurentian Plateau, or Bouclier canadien (French), is a large area of exposed Precambrian igneous and high-grade metamorphic </span>rocks<span> (geological </span>shield<span>) that forms the ancient geological core of the North American continent (the North American Craton or Laurentia).</span>
Answer:
-50 N
Explanation:
Givens:
V_i = 36 km/h
V_f = 18 km/h
t = 2 s
m = 20 kg
First we have to convert our km/h into m/s:
(36 km*(1000 m/1 km)) / (60 min *(60 s/1 min)) = 10 m/s
(18 km*(1000 m/1 km)) / (60 min *(60 s/1 min)) = 5 m/s
a = (V_f - V_i)/t
a = (5 m/s - 10 m/s) / 2 s
a = -2.5 m/s^2
F = m(a)
F = 20 kg(-2.5 m/s^2)
F = -50 N
It's a negative force meaning its acting on it opposite its current direction of movement.
