Respuesta :
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 .
Based on the magnitude of normal force acting on them, the ranking from largest to smallest will be:
- 150N--->7kg = 150N--->1kg.
- 140N--->5kg = 140N--->3kg.
- 130N--->7kg.
- 120N--->3kg.
Based on the masses, the frictional force acting on the boxes will be such that the ranking from largest to smallest will be:
- 150N--->7kg = 130N--->7kg.
- 140N--->5kg
- 140N--->3kg = 120N--->3kg
- 150N--->1kg
Normal force magnitude
The normal forces acting on the box will depend on the force acting on the box. This means that the larger the force acting on the box, the larger the normal force.
This is why the box with a force of 150 N will be have the highest normal force acting on it.
Frictional force magnitude
The frictional force acting on the boxes will depend on the mass. Boxes will lager masses will have more frictional force acting on them.
The boxes of 7kg will therefore have the largest frictional forces acting on them.
Find out more on frictional forces at https://brainly.com/question/24386803.