on touching electroscope gets positively charged, so answer is B. conduction
Answer:
11.8 m/s
Explanation:
At the top of the hill, there are two forces on the car: weight force pulling down (towards the center of the circle), and normal force pushing up (away from the center of the circle).
Sum of forces in the centripetal direction:
∑F = ma
mg − N = m v²/r
At the maximum speed, the normal force is 0.
mg = m v²/r
g = v²/r
v = √(gr)
v = √(9.8 m/s² × 14.2 m)
v = 11.8 m/s
Answer:
(B) the sum total of all matter and energy
Explanation:
Universe comprises of all the matter and energy that exists in space. It contains billions of stars, planets and interstellar matter that is clouds of dust and gas. There is large amount of the empty space in between.
Universe contains stars as many as grains of sand on all beaches on the Earth. These stars are grouped into galaxies. Milky Way is one of the galaxies. Galaxies can be grouped into clusters and super-clusters.
<span> the angle of reflection is
30 degrees</span>
