Physics Forces

Complete the following statement: The term net force most accurately describes...
a) the inertia of an object.
b) the quantity that causes displacement.
c) the mass of an object.
d) the quantity that keeps an object moving.
e) the quantity that changes the velocity of an object.

Complete the following statement: The term net force most accurately describes...
a) the inertia of an object.
b) the quantity that causes displacement.
c) the mass of an object.
d) the quantity that keeps an object moving.
e) the quantity that changes the velocity of an object.

e) the quantity that changes the velocity of an object.

Which one of the following terms is used to indicate the natural tendency of an object to remain at rest or in motion at a constant
speed along a straight line?
a) velocity
b) equilibrium
c) acceleration
d) inertia
e) force

d) inertia

Which one of the following statements concerning Newton's first law of motion is false?
a) If no force acts on an object, the object's velocity cannot change.
b) If no net force acts on an object, the object cannot accelerate.
c) All objects in motion have forces acting on them.
d) All of the answers above are false.

c) All objects in motion have forces acting on them.

A net force 4N is required to give an object with mass m an acceleration 2a. If the net force is applied to an object with mass 2m, what is the acceleration on this object?
a) a
b) 2a
c) 3a
d) 4a
e) 6a

a) a

Complete the following statement: The net force that results when two or more forces act on an object is
a) determined by adding the magnitudes of the individual forces. The direction of the net force is the same as the direction of
motion.
b) the largest force acting on the object.
c) determined using vector addition of the individual forces acting on the object.
d) the magnitude of the largest force acting on the object. The direction of the net force is the same as the direction of motion.

c) determined using vector addition of the individual forces acting on the object.

A rock is thrown straight up from the earth’s surface. Which one of the following statements concerning the net force acting on
the rock at the top of its path is true?
a) It is instantaneously equal to zero newtons.
b) It is greater than the weight of the rock.
c) It is less than the weight of the rock, but greater than zero newtons.
d) Its direction changes from up to down.
e) It is equal to the weight of the rock.

e) It is equal to the weight of the rock.

Ryan walked to a cliff and dropped a stone. Neglecting any effects due to the air as it falls vertically, which one of the
following is the reaction force to the Earth's gravity on the stone?
a) the normal force of the ground below
b) the normal force of Ryan's hand on the stone
c) the gravitational force of the stone acting on the Earth
d) No reaction force appears in this situation since the stone is not exerting any forces on anything else.

c) the gravitational force of the stone acting on the Earth

The magnitude of the weight of an object is always the same as which of the following quantities?
a) F N , the magnitude of the normal force acting on the object
b) the net force acting on the object
c) mg, the object's mass times the acceleration due to gravity
d) W - F N , the weight of the object minus the normal force
e) ma, the object's mass times its acceleration

c) mg, the object's mass times the acceleration due to gravity

16. A small plane increases its altitude by flying with a constant velocity at an angle ϕ with respect to the horizontal. Which one of
the following statements is true concerning the magnitude of the net force on the plane?
a) It is equal to the weight of the plane.
b) It is equal to the magnitude of the force of air resistance.
c) It is equal to zero newtons.
d) It is less than the weight of the plane but greater than zero newtons.
e) It is equal to the component of the weight of the plane in the direction of motion.

e) It is equal to the component of the weight of the plane in the direction of motion. ???????????

A block is pulled at constant speed along a rough level surface by a rope that makes an angle with respect to the horizontal.
The applied force along the rope is P. The force of kinetic friction between the block and the surface is f. Which one of the
following actions will increase the frictional force on the block?
a) increasing the angle made by the rope
b) decreasing the speed of the block
c) decreasing the contact surface area
d) increasing the contact surface area
e) increasing the weight of the block

e) increasing the weight of the block