Gravity causes the motions of planets, stars, and galaxies. It's why the Moon orbits around the Earth, and the Earth orbits around the Sun, and the solar system orbits around the galaxy.
Answer:
option C
Explanation:
given,
force act on west = 20 lb
force act at 45° east of north = 80 lb
magnitude of force = ?
∑ F y = 80 cos 45⁰
F y = 56.57 lb
magnitude of forces in x- direction
∑ F x = -20 + 80 sin 45⁰
= 36.57 lb
net force
F = 
F = 
F = 67.36 lb≅ 67 lb
hence, the correct answer is option C
... find length
(way 1) determine acceleration using force
only force act on skier is mg vertically. spilt vector we get force along the incline = mgsin(10) and f= ma so
ma = mgsin(10) or a = gsin(10)
a (along the incline)= gsin(10) = 10sin(10) = 1.74
v^2 = u^2 + 2as
15^2 = 3^2 + 2(1.74)s
s = 62.06 m
(way 2) using conservation of energy
energy (KE+PE) on top = energy at bottom
0.5m3^2 + mgh = 0.5m15^2 +0
h (height of incline) = (112.5 - 4.5)/10 = 19.8 m
length of incline = h/sin(10) = 62.2 m ; trigonometry
... find time
s = (u+v)t/2
t = 2s/(u+v) = 2(62.2)/(3+15) = 6.91 s
Answer:
An atom is the smallest part of an element by itself, while molecules are built of multiple atoms.
Answer:
Yes option A is right.
Explanation:
As we know that the "Opposite charges attract and like charges repel eachother". So based upon that fact we find out the sphere will be repelled or attract by the rod. As in this case metallic sphere was neutral initially but then we touched the rod with it. Although it was for few seconds but the charge is transferred to the sphere. Now both sphere and the rod have charge. After the seperation we look towards their respond If both have the opposite charge they will attract eachother. But here in this case they repel because they have the same charge, as we have charged the neutral sphere with the rod so we already know that they have the same charges that is why they are repelling eachother.
Insulation from the ground means that blocking the way of charges or free electrons from earth to metallic sphere and vice versa. As there exists free electrons and charges in earth they would flow into the metallic objects. So for more precise and accurate experiments we insulate the metals or prevent the metals from touching the earth surface to avoid the flow of charges through them. I hope it will help you.
