26 terms

Conceptual Physics - Ch 4 - Newton's 2nd Law

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Terms in this set (...)

Force
Any influence that can cause an object to be accelerated, measured in Newton's
Friction
The resistive force that opposes the motion or attempted motion of an object either past another object with which it is in contact
Mass
The quantity of matter in an object (stuff). More Specifically, it is the measure of the inertia.
Weight
The force due to gravity on a object (mg)
Volume
The quantity of space an object occupies
Newton's Second Law
The acceleration of an object is directly proportional to the net force acting on the object, is in the direction of the net force, and inversely proportional to the mass of the object
Newton
The SI unit of Force (N) - One newton is the force that will give an object of mass 1 kg an acceleration of 1 m/s
Kilogram
Unit of Mass
Free Fall
Motion under the influence of gravitational pull
Terminal Speed
The speed at which the acceleration of a falling object terminates because air resistance balances its weight. When direction is specified, then we speak of terminal velocity
a) less
Compared to its weight on earth, a 10-kg object on the moon will weigh ___________
a) less
b) more
c) the same
c) the same
Compared to its mass on earth, the mass of a 10-kg object on the moon is ___________
a) less
b) more
c) the same
c) 20 N
A 10-N force and a 30-N force act on an object in opposite directions. What is the net force on the object?
a) 40 N
b) 30 N
c) 20 N
d) 10 N
e) 0 N
a) Velocity decreased
You are standing in a moving bus, facing forward, and you suddenly fall forward. You can imply from this that the bus'
a) Velocity decreased
b) velocity increases
c) speed remained the same, but it's turning right
d) speed remained the same, but it's turning left
b) inversely proportional
How does acceleration of an object change in relation to its mass? It is _______________
a) directly proportional
b) inversely proportional
c) acceleration doesn't depend on mass at all
c) 10 N
Suppose the force of friction on a sliding object is 10N. The force needed to maintain a constant velocity is _________________
a) more than 10 N
b) less than 10 N
c) 10 N
c) in equilibrium
If the forces on an object are balanced, we say that the object is _______________
a) accelerating
b) inertia
c) in equilibrium
d) velocity
b) 3.0 m/s^2
A girl pulls on a 10-kg wagon with a constant net force of 30 N. What is the wagon's acceleration?
a) 0.3 m/s^2
b) 3.0 m/s^2
c) 10 m/s^2
d) 30 m/s^2
e) 300 m/s^2
c) It halves
Suppose a cart is being moved by a force. If suddenly a load is dumped into the cart so that the cart's mass doubles, what happens to the cart's acceleration?
a) it quadruples
b) it doubles
c) It halves
d) it quarters
e) it stays the same
b. To nearly its original height
Galileo found that a ball rolling down one inclined plane would roll how far up another inclined plane?
a. The ball would not roll up the other plane at all.
b. To nearly its original height
c. To about one quarter its original height
d. To nearly twice its original height
e. To nearly half its original height
e. will do all of the above.
The law of inertia states that an object
a. will continue moving at the same velocity unless an outside force acts on it.
b. will continue moving in a straight line unless an
outside force acts on it.
c. that is not moving will never move unless a force
acts on it.
d. at rest will remain at rest unless acted on by an
outside force.
e. will do all of the above.
c. both moving and nonmoving objects.
The law of inertia applies to
a. objects at rest.
b. moving objects.
c. both moving and nonmoving objects.
a. zero, since no force is necessary to keep it moving.
After a cannonball is fired into frictionless space, the amount of force needed to keep it going equals
a. zero, since no force is necessary to keep it moving.
b. twice the force with which it was fired.
c. one half the force with which it was fired.
d. the same amount of force with which it was fired.
e. one quarter the force with which it was fired.
b. less.
Compared to its weight on Earth, a 10-kg object on the moon will weigh
a. the same amount.
b. less.
c. more.
a. the same.
Compared to its mass on Earth, the mass of a 10-kg object on the moon is
a. the same.
b. more.
c. less.
b. 11 kg.
The mass of a sheep that weighs 110 N is about
a. 1 kg.
b. 11 kg.
c. 110 kg.
d. 1100 kg.
e. none of the above