Question

understanding newton's law
1. An object cannot remain at rest unless which of the following holds?

a. The net force acting on it is zero.
b. The net force acting on it is constant and nonzero.
c. There are no forces at all acting on it.
d. There is only one force acting on it.

which one is the answer? there can be more than one answer....

2. If a block is moving to the left at a constant velocity, what can one conclude?

a. There is exactly one force applied to the block.
b. The net force applied to the block is directed to the left.
c. The net force applied to the block is zero.
d. There must be no forces at all applied to the block.

which one is the answer? there can be more than one answer.....

3. A block of mass 2 kg is acted upon by two forces: 3 N (directed to the left) and 4 N (directed to the right). What can you say about the block's motion?

a. It must be moving to the left.
b. It must be moving to the right.
c. It must be at rest.
d. It could be moving to the left, moving to the right, or be instantaneously at rest.

which one is the answer? there can be more than one answer......

4. A massive block is being pulled along a horizontal frictionless surface by a constant horizontal force. The block must be __________.

a. continuously changing direction
b. moving at constant velocity
c. moving with a constant nonzero acceleration
d. moving with continuously increasing acceleration

which one is the answer? there can be more than one answer.........

5. Two forces, of magnitude 4\;\rm N and 10\;\rm N, are applied to an object. The relative direction of the forces is unknown. The net force acting on the object __________.

Check all that apply.

cannot have a magnitude equal to 5 N
cannot have a magnitude equal to 10 N
cannot have the same direction as the force with magnitude 10 rm N
must have a magnitude greater than 10 rm N