Newton's 1st Law Net Force

If an object remains at rest what must be true?

• The weight of the object must be zero.

• A friction force must act on the object.

• At least one normal or support force must act on the object.

• The sum of all forces acting on the object must be zero.

All the following statements are ALWAYS TRUE about an object that has zero acceleration EXCEPT one. Which statement might be false?

• The object is at rest.

• The object's velocity is constant.

• The net force acting on the object is zero.

• Any frictional forces acting on the object are balanced by equal and opposite forces.

Tags

NGSS.HS-PS2-1

A skater glides across the ice in a straight line. To maintain her speed she must push against the ice every so often. The pushes are necessary because

• the ice is perfectly frictionless.

• she needs to maintain her state of zero acceleration.

• a small force is needed to overcome friction cause by sliding on the ice.

If the net force on a block is zero, then

• No forces act on the block.

• There is no friction on the block.

• The block has zero velocity.

• The object has zero acceleration.

Tags

NGSS.HS-PS2-1

Objects with more mass have less inertia.

• True

• False

Inertia is the tendency of an object at rest to stay at rest.

• True

• False

The more velocity an object has, the greater its inertia.

• True

• False

Inertia is the tendency of an object in motion to stay in motion.

• True

• False

According to the first law, an object at rest . . .

• accelerates inversely proportion to its mass.

• remains at rest because it has zero acceleration.

• remains at rest unless acted upon by a net force.

• remains at rest due to the constant presence of friction.

According to the first law, an object in motion remains in motion . . .

• forever.

• at the same speed.

• with acceleration inversely proportional to its mass.

• at the same speed and in the same direction unless acted upon by a net force.