Answer:
Explanation:
When a body is held against a vertical wall , to keep them in balanced position , normal force is applied on their surface . this force creates normal reaction which acts against the normal force and it is equal to the normal force as per newton's third law . Ultimately friction force is created which is proportional to normal force and it acts in vertically upward direction . It prevents the body from falling down .
Hence normal force = reaction force .
From second law also net force is zero , so if normal force is N and reaction force is R
R - N = mass x acceleration = mass x 0 = 0
R = N .
Ranking normal force from highest to smallest
150 N , 130 N , 120 N
B )
Frictional force is equal to the weight of the body because the body is held at rest .
Ranking of frictional force form largest to smallest
7 kg , 5 kg , 3 kg , 1 kg .
Here frictional force is irrespective of the normal force acting on the body because frictional force adjusts itself so that it becomes equal to weight in all cases here because it always balances the weight of the body .
Answer:
No
Explanation:
There is no limit to how fast the universe can expand, says physicist Charles Bennett of Johns Hopkins University. Einstein's theory that nothing can travel faster than the speed of light in a vacuum still holds true, because space itself is stretching, and space is nothing.
Answer:F=4F
Explanation: Columbs law states that The force between the two point charges is directly proportional to the product of charges and inversely proportional to the square of distance between them
Force between the two charges is given by
F=K*q1*q2/r^2
if one charge become 4 times, new force is,
F=4(K*q1*q2)/r^2
F=4F
Where q1 and q2 are the point charges
r is the distance between the two charges
K is a constant of proportion called electrostatic force
1)
HCl: hydrogen, chloride
3CO2: carbon, oxygen
2Na2SO4:sodium, sulphur, oxygen.
2)
-HCl: 1 hydrogen atom, 1 chlorine atom
-CO2: 1 carbon atom, 2 oxygen atoms
-Na2SO4: 2 sodium atoms, 1 sulphur atom, 4 oxygen atoms.
3)
-HCl: 2 atoms
-3CO2: 9 atoms
-2Na2SO4: 14 atoms.
