chapter 2
The minimum number of forces that act on a book resting on a table is
two
the net force on any object in equilibrium is
zero
Jason weighs 150 N and sits on his big brother's shoulders. Big brother weighs 400 N. The support force supplied by the floor must be
550 N
The support force on a 10-N book at rest on a table is
10-N
A block pulled to the left with 15-N and to the right with 5N at the same time experiences a net force of?
10N
An 800-N man stands at rest on two bathroom scales so that his weight is distributed evenly over both scales. The reading on each scale is
400N
When a pair of 10-N forces act on a box of candy, the net force on the box is
anything depending on the direction of the forces
If you toss a coin straight upward while in a train moving at constant velocity, the coin will land
as if you were at rest
a hockey puck sliding at constant velocity across the ice is
in equilibrium
Tablecloth trick
inertia
a sheet of paper can be quickly jerked beneath a container of milk without toppling, which best demonstrates
inertia
A force is a vector quantity because
it has both magnitude and direction
which of the following is a vector quantity? (volume;area;mass)
non of them
when no forces act on a moving objects their path are normally
straight lines
The first scientist to introduce the concept of inertia was
Galileo
A package falls off a truck that is moving at 30m/s. neglecting air resistance, the horizontal speed of the package just before it hits the ground is
about 30 m/s
The scientist credited for formulating a model in which the earth circles the sun is
copernicus