PHYSC
A rock is thrown vertically into the air. At the top of its path, its acceleration is
0
Two billiard balls having the same mass and speed roll toward each other. What is their combined momentum after they meet?
0kg-m/s
Exert 1 N for a distance of 1 m in 1 s and you deliver a power of
1 Work
A baseball player bats a force with 1000N. The ball exerts a reaction force against the bat of
1000N (action and reaction forces are the same)
Starting from rest, the distance a freely falling object will fall in 10 seconds is about
100m = (10 seconds) x (10N)
Ten seconds after starting from rest, a freely falling object will have a speed of about
100m/s= (10seconds)x(10N)
The gain in speed each second for a freely falling object is about
10m/s (10N gravity)
A 1-kg chunk of putty moving at 1m/s collides and sticks to a bowling ball initally at rest. The bowling ball and putty then move with a momentum of?
1kg/m/s
The mass of a pet turtle that weighs 10N is
1kg= (10g)/(10N)
Compared to your weight on Earth, your weight on Jupiter would be about
2 times (24.79)
A 5kg fish swimming at a speed of 1 m/s swallows a 1kg fish swimming at 4m/s The speed of the larger fish now is
2/3m/s
A car has a mass of 1000 kg and accelerates at 2 meters per second squared. What is the magnitude of the net force exerted on the car?
2000N = (1000kg)x(2m/s/s)
The average speed of a horse that gallops 10 kilometers in 30 minutes is
20km/h = (10km)x(30minsx2)
A car traveling at 22 m/s comes to an abrupt halt in 0.1 second when it hits a tree. What is the deceleration of the car?
220=(22m/s)/(.1s)
On the surface of Jupiter, the acceleration due to gravity is about 3 times that of Earth. What would be the mass of a 100-kg rock on Jupiter?
3000N=(3x10g)x(100kg)
A 300kg bear grasping a vertical tree slides down at a constant velocity. The friction force between the tree and the bear is
30N= (300kg)/(10N)
a 4kg ball has a momentum of 12kg-m/s whats the balls speed?
3m/s= (12kg-m/s)/(4kg)
The age of the sun is about
5 Billion yrs
a 5 kg fish swimming at a speed of 1m/s swallows an absent minded fish at rest. The speed of the larger fish after lunch is
5/6 m/s
What is the force of gravity on a 500-N woman standing on Earth's surface?
500N
The weight of a .6kg salami is about
6.0 N= (.6)x(10grav)
It takes 6s for a stone to fall to the bottom of a mineshaft. How deep is the shaft?
60m= (10N)x(6s)
A 10N falling object encounters 4N of air resistance. The magnitude of the net force on the object is
6N= 10N-4N
Earth pulls on the moon. Similarly the moon pulls on Earth, evidence that
Earth and the moon are simply pulling on each other because of action-reaction pairs
The scientist to first introduce the concept of inertia was
Galileo
newton discovered
Gravity is universal
If the sun were twice as massive
It's pull on Earth would double and the pull of Earth on the Sun would double
When the alignment of the Sun, the Moon, and Earth produce a solar eclipse, the body between the other two is the
Moon
Impulse-momentum relationship is a direct result of
Newton's second law
The predominant gas in the atmosphere of Earth is
Nitrogen (76%)
It is correct to say that impulse is equal to
a corresponding change in momentum
Action and reaction forces comprise the parts of
a single interaction
In science, a theory is
a synthesis of a large body of well-tested knowledge
When you jump from an elevated position you usually bend your knees upon reaching the ground, which makes the time of the contact about 10 times that of a stiff-legged landing. In this way the average force your body experiences is
about 10 times
Disregarding air resistance, objects fall with constant
acceleration
While a car travels around a circular track at a constant speed, its
acceleration is zero
An object maintains its state of motion because it has
acceleration, mass, weight, and speed
with respect to the stars, the moon
and the earth circle each other
An archer shoots an arrow. Consider the action force to be the bowstring against the arrow. The reaction to this force is the
arrow's push against the bow string
Which has zero acceleration? An object
at rest, moving at constant velocity, in mechanical equilibrium
No greenhouse effect occurs on Mercury because of no
atmosphere
Evidence of the solar wind on Earth is the
aurora borealis
the general direction of a comet's tail is
away from the sun
the solar wind blows in a direction
away from the sun
Earth's gravitational field extends
both inside and outside the Earth and throughout the entire universe
Which requires more work: lifting a 70-kg sack vertically 2 meters or lifting a 35-kg sack vertically 4 meters?
both require the same work. (70)(2)= 140 (35)(4)= 140
A cannon recoils from launching a cannonball. The speed of the cannon's recoil is small because the
cannon has more mass than the ball
The two measurements necessary for calculating average speed are
distance and time
An object is propelled along a straight line path by force. If the net force were doubled, it's acceleration would
double
the reason that the moon takes on a crescent shape each month has to do with the
earth's shadow
an object at rest may have
energy
Whereas Aristotle relied on logic in explaining nature, Galileo relied on
experiment
An Earth satellite is in an elliptical orbit. The satellite travels fastest when it is
farthest from the earth
Whirl a rock at the end of a string and it follows a circular path. If the string breaks, the tendency of the rock is to
follow a straight-line path
a moving object on which no forces are acting will continue with constant
impulse, momentum, acceleration
If the mass of Earth somehow increased with no change in radius, your weight would
increase also
the parts of saturn's rings with the greatest rotational speed are the
inner parts
with each pass of a comet about the sun, its mass
is appreciably reduced
A rock is thrown vertically into the air. At the very top of its trajectory the net force on it is
its weight
Compared to a recoiling rifle, the bullet that is fired has a greater
kinetic energy
compared to the density water, the density of saturn is
less
a bow is drawn so that is has 40 J of potential energy. When fired, the arrow will ideallly have a kinetic energy of
less than 40J
Compared with falling on a wooden floor, a wine glass may not break when it falls on a carpeted floor because the
longer time to stop
A force is a vector quantity because it has both
magnitude and direction
A kilogram is a measure of an objects
mass
Compared with a 1kg block of solid iron, a 2kg solid block of iron has twice as much
mass, volume, and inertia
Two objects, A and B, have the same size and shape, but A is twice as heavy as B. When they are dropped simultaneously from a tower, they reach the ground at the same time, but A has a higher
momentum
Which is most responsible for the ocean tides?
moon
An object that has kinetic energy must be
moving
the predominant gas in thhe atmosphere of venus is
nitrogen
The Sun tends to bloat outward by nuclear fusion, and contract due to
nuclear fission
Totality during a solar eclipse is not totally dark because
of light from the solar corona
A 10N block and 1 N block lie on a horizontal frictionless table. To push them with equal acceleration, we would have to push with
one-tenth as much force on the heavier block
a satelite in an eliptical orbit travels at constant
speed, velocity, acceleration
Comets orbit about the
sun
No work is done by gravity on a bowling ball that rolls along a bowling alley because
the force on the ball is at right angles to the ball's motion
Your weight is
the gravitational attraction between you and the earth, a property of mechanical equilibrium, actually your mass
A sheet of paper can be withdrawn from under a container of milk without toppling it if the paper is jerked quickly. The reason this can be done is that
the milk carton has inertia
The fastest moving planet in a solar system is
the planet nearest the sun
A ball is thrown vertically into the air. Because of air resistance, its time coming down compared to its time going up is
the same
Compared with the same mass of a certain object on earth, the mass of the same object on the moon is
the same
A 10kg brick and a 1kg brick are dropped in a vaccum. The force of gravity on the 10kg brick is
the same as the force on the 1kg brick
The speed of planets about the sun depend on
their distances from the sun
In order to catch a ball, a baseball player extends the hand forward before impact with the ball and then lets it ride backward in the direction of the ball's motion .. Doing this reduces the force of impact on the player's hand principally because the
time of impact is increased
An object is raised above the ground gaining a certain amount of potential energy. If the same object is raised twice as high, it gains
twice as much potential energt
If you push an object twice as far while applying the same force, you do
twice as much work
Tidal forces in general are the result of
unequal forces acting on different parts of a body
the planet that is most tipped to its orbital plane is
uranus spins at 98 degrees (on its side)
As an object free falls its
velocity and acceleration increases
The planet with a mass most like earths is
venus
If the speed of an object doubles, what else doubles?
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