EFHS -- Newtons Law

If an object is "at rest", can we assume no forces are acting on it?

• yes, because the object is not moving

• yes, because friction holds the object in place

• no, because gravity acts on all objects on Earth at all times

• no, because the normal force cancels out the force of gravity

An object at rest will remain at rest unless acted upon by a net force.  This statement of Newton’s first law can be referred to as _____.

• The Action-Reaction law

• The Law of Unintended Consequences

• The Law of Inertia

• The Law of Conservation of Energy

Newton's second law of motion relates which variables?

• force, mass, and acceleration

• force, friction, and inertia

• force, mass, and weight

• action and reaction forces

  A 5.5 kg stack of books is pushed across a table.  If the acceleration of the books is 4.2 m/s² to the right, find the net force exerted on the books. 

• 55.8 N

• 5.5 N

• 1.3 N

• 23.1 N

Which type of force tries to hold a stationary object in place?

• kinetic friction    

• normal force 

• weight 

• static friction

In which direction does the normal force act on an object?

• toward the center of the Earth

• in the opposite direction of motion

• perpendicular to the contact surface

• in the same direction as the motion of the object

You push a 50 kg block with 30 N of force.  What is the acceleration of the block?

• 1500 N

• 0.6 m/s²

• 15.00 m/s²

• 1.667 N

A builder uses a hammer to hit a nail.  During the collision, there is a force _____.

 

• on the hammer but not on the nail

• on the nail but not on the hammer

• on the wall behind the nail only

• on the nail from the hammer, and on the hammer from the nail

Name the missing force...

• frictional force
• weight force
• thrust
• buoyant force

Name the missing force...

• weight force
• normal force
• applied force
• frictional force