46 terms

Physics Final

Professor Batley POP 101 Chapters 1-5
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The net force of any object in equilibrium is
Zero
If you have snow on your boots, you can get the snow off by stomping your boots on the floor. This is according to the law of
Inertia
If you exert a horizontal 100 N force on a crate and it slides along a factory floor at a constant speed, then the friction between the crate and the floor is
100 N
Hang on a rope and you put tension in it. Stand on a brick and you put ______________ in it.
Compression.
Speed is always measured in units of distance and
time.
The thing that distinguishes velocity from speed is
direction.
Galileo discovered that something remains unchanged for balls rolling down inclined planes. What remains the same as the motion progresses?
A change in speed is the same in equal times.
Toss a ball up at 30 m/s and air drag is negligible, the ball will be in the air for
6 seconds
The hang time of a pro b-ball player is usually
less than a second.
Consider a cart pushed along a track with a certain force. If the force remains the same while the mass decrease to half, the acceleration of the cart _____?
doubles
Push a cart along a track so twice as much net force acts on it. If acceleration remains the same what is the reasonable explanation?
The mass of the cart doubled when the force doubled.
When a 25 N falling object encounters 15 N of air resistance, the net force is
10 N
As a falling object gains speed in falling, the air drag on it _____?
increases
Toss a rock straight up in the air, and at the top of its path its acceleration is ____________?
g
Can a boxer exert a force of 50 N on a piece of paper? The tissue paper is mid air with no wall.
No, it can NOT be done.
The force exerted on a the tires of a car to directly accelerate it along the road is exerted by the
pavement
The team that wins the tug-of-war is the team that
pushes harder on the ground
A massive fast moving car collides with a light slow moving car, the acceleration is great for?
It the same for both.
An airplane's speed across the ground can be affected by the wind. When a plane experiences a cross wind the speed of the plane across the ground below is
increased.
Suppose Nellie hangs from two strands of rope the form equal angles to the vertical, the tension in the rope may be ______________ than her weight?
more or less
What is the scientific method?
The general process by which we explore science - eliminating human bias.
What is Newtons 1st?
An object in motion tends to stay in motion (unless acted on by outside force) and an object at rest tends to stay at rest (unless acted on by outside force).
Suppose you and a pair of life preservers are floating down a swift river, as shown. You wish to get to either of the life preservers for safety. One is 3 meters downstream from you and the other is 3 meters upstream from you. Which can you swim to in the shortest time?
Both require the same.
Tracks A and B are made from pieces of channel iron of the same length. They are bent identically except for a small dip near the middle of Track B. When the balls are simultaneously released on both tracks as indicated, the ball that races to the end of the track first is on
Track B.
An airplane makes a straight back-and-forth round trip, always at the same airspeed, between two cities. If it encounters a mild steady tailwind going, and the same steady headwind returning, will the round trip take
More.
What is Newton's 2nd?
Sum of forces = mass x acceleration
Sum of forces -> net force
For the same force
Smaller mass, has larger acceleration
Larger mass, has smaller acceleration
F=ma
Galileo is credited with being the first to identify the concept of inertia and the first to develop the concept of acceleration. And like others, he discussed forces. But he didn't connect these basic concepts. Which law of Newton makes the connection that Galileo missed?
2nd law of motion
Two identical spring-loaded dart guns are simultaneously fired straight downward. One fires a regular dart; the other a weighted dart. Which dart hits the ground first?
The Regular dart.
Which encounters the greater force of air resistance—
Elephant
Two smooth balls of exactly the same size, one made of wood and the other of iron, are dropped from a high building to the ground below. The ball to encounter the greater force of air resistance on the way down is
the iron ball
As a woman falls faster and faster through the air, her acceleration
decreases
What is Newton's 3rd?
For every action there is an equal and opposite reaction
I cannot push on you any harder than you push on me
A bug and a bus feel the same force upon impact
Arnold Strongman and Suzie Small pull on opposite ends of a rope in a tug of war. The greater force exerted on the rope is by
Neither. The force is the same.
Suppose a cannon is propped against a massive tree to reduce recoil when it fires. Then the range of the cannonball will be
Increased
Define Inertia
the property of things to resist changes in motion
Define force
a push or a pull
Net Force is
the vector sum of force that act on a n object
Mechanical Equilibrium is
the state of an object of system of objects for which there are no changes in motion
Instantaneous speed
is the speed at any instant
Vector quantity is
quantity that has both magnitude and direction.
free fall
is motion under the influence of gravity only
scalar quantity is
quantity that can be described by magnitude w/o direction.
Volume is
the quantity of space an object occupies.
Define terminal speed
the speed at which the acceleration of a falling object terminates because air resistance balances its weight. If it has direction specified it is called TERMINAL VELOCITY.
A vector is
an arrow drawn to scale used to represent am vector quantity.
A Resultant is
the net result of a combo of two or more vectors