final exam Flashcards
a humming bird flying at 4 km/h that gets caught in a 3 km.h crosswind, what is the resultant speed
5 km/h, pythaogrem theorom, tail to tip
what is not a vector quantity
speed
a mosquito flying at 3 m/s that encounters a breeze blowing at 3 m/s in the opposite direction
has a speed of
0
A mosquito flying at 3 m/s that encounters a breeze blowing at 3 m/s in the same direction has a
speed of
6
It there were no gravity, a stone thrown upward at 45° would follow a straight line path. Because
of gravity, at the end of 1 second, the stone is actually
-5, y=-1/2gt^2
A bullet fired horizontally from a rifle begins to fall
as soon as it leaves the barrel
The amount of force needed to sustain motion of a rock in outer space is
nothing is required
When no forces act on moving objects, their paths are normally
straight line motion
A 300-kg bear grasping a vertical tree slides down at constant velocity. The friction force
between the tree and the bear is
3000 N
A 5-N falling object encounters 5 N of air resistance. The net force on the object is
0
According to Isaac Newton, the greater the masses of interacting objects, the
greater gravitational force between them
According to Newton, when the distance between two interacting objects doubles, the
5
gravitational force is
1/4
The work you do when pushing a shopping cart a given distance while applying twice as much
force is
twice as much
The work done in pushing a TV set a distance of 2 m with an average force of 20 N is
40 J
he mass of a ball moving at 3 m/s with a momentum of 48 kg-m/s is
16
freight train rolls along a track with considerable momentum. If it rolls at the same velocity but
has twice as much mass, its momentum is
twice
our pet hamster sits on a record player that has constant angular velocity. If the hamster moves
to a point twice as far from the center, then its linear speed
doubles
If a turntable’s rotational velocity is doubled, then the linear velocity of a pet hamster sitting on
the edge of the record will
double
The equilibrium rule, , applies to
objects at rest or systems 8in uniform motion
The equilibrium rule applies to
vector quanitites
Radio waves travel at the speed of light, or 300,000 km/s. The wavelength of a radio wave
received at 100 megahertz is
3 m
A 60-vibration-per-second wave travels 30 meters in 1 second. Its frequency is
60 hertz and it travels at 30 m/s.
Water waves pass by a piece of cork floating on the water that bobs up and down one complete
cycle each second. The waves are 2 meters long. What is the speed of the wave?
2 m/s
A skipper on a boat sees wave crests passing the anchor chain every 5 seconds and estimates the
distance between crests is 15 m. What is the speed of the water waves?
3 m/s
