physics midterm
the net force on any object in equilibrium is...
0
a 10 N book us at rest on a flat table. how many newtons of support force does the table provide?
10 N
If you exert a horizontal 100-N force on a crate and it slides along a factory floor at constant speed, then the friction between the crate and the floor is...
100 N
what is the net force on an object that is pulled to the right with a force of 30 pounds and to the left with a force of 10 pounds?
20 pounds to the right
burl has moved toward the left end of the staging. what does the right scale now read?
200 N
if a 100 lb person steps on a pair of bathroom scales and leans so that the reading on one scale is 60 lbs, the reading on the other scale is...
40 lbs
Burl is standing exactly in the middle of the staging. the left scale reads 400 N. what does the right scale read?
400 N
ed weighs 600 N, the reading on the left scale is 700 N, and the reading on the right is 300 N. what is the weight of the staging?
400 N
in mathematical notation, the equilibrium rule is...
EF=0
a package falls off a truck that is moving at 30 m/s. neglecting air resistance, the horizontal speed of the package just before it hits the ground is...
about 30 m/s
Galileo used balls rolling on inclines to demonstrate what?
an object's natural tendency is to continue at a constant speed
how many forces are acting on the book sitting flat on a table?
at least two forces
on a cold winter day mr. peer is driving his car around a gently curving road at a constant speed when he unexpectedly passes over a section of ice covered road which provides absolutely not friction for the tires. the tendency of the car is to...
follow a straight line path
as peer carries a small sand bag across the room, what keeps it moving in a straight line at a constant speed?
inertia
it is said that "the early bird catches the worm." of Copernicus was correct. how is it that the early bird in the tree can catch the worm on the ground?
inertia makes it easy
on a cold winter day mr. peer slips on ice and slides down the sidewalk with constantly increasing speed. faster and faster he goes until the signpost at the bottom of the sidewalk brings his adventure to a sudden halt. prior to hitting the sign post, is he in mechanical equilibrium?
no
according to Aristotle, the normal state of an object on earth is a state of...
rest
Copernicus was known for what theory?
the earth circles the sun
a bowling ball rolls down the alley in a straight line at constant speed. is the ball in a state of equilibrium?
yes
what is the net force on the book sitting flat on a table?
zero