If the net force acting on an object is zero, it a. stays at rest if it were at
ID: 1640390 • Letter: I
Question
If the net force acting on an object is zero, it a. stays at rest if it were at rest before, stops if it were moving before. b starts moving if it were at rest before: stops if it were moving before. c. stays at rest if it were at rest before: keeps on moving if it were moving before. d. starts moving if it were at rest before: keeps on moving if it were moving before. e. may or may not remain at rest if it were at rest before: stops if it were moving before. The normal force is a. always vertically downward b. always perpendicular to the surface of contact c. always parallel to the surface of contact d. always equal to the weight of the object e. only present if the object is at rest. You push against a wall with a force of 100 N. The force that the wall applies on you is a. 50 N b. 200 c. 0 d. -100 N e. cannot be determined unless the material used to construct the wall is known. When a net force of 10 N is applied to an object, it accelerates at 2 m/s^2. Mass of the object is a. 10 kg b. 20 kg c. 5 kg d. 0.2 kgExplanation / Answer
1.
Net force is zero, means
Fnet = m*a = 0
means acceleration of object is zero.
So if object is initially at rest then it will stay at rest.
If object is moving with zero acceleration (constant velocity) then object will continue moving with constant velocity.
Correct option is C.
2.
Normal force is always perpendicular to the surface of contact.
Correct option is B.
3.
Using newton's third law, every action has equal and opposite reaction.
wall applies -100 N force on you
Correct option is D.
4.
Using the equation
F = m*a
m = F/a
m = 10/2 = 5 kg
Correct option is C.