01 HW
A mosquito flying at 3 m/s encounters a 3-m/s breeze blowing in the opposite direction, which gives it a resulting speed over the ground of
0 m/s
The support force on a 10-N book that rests on a horizontal surface is
10
If a freely falling object were somehow equipped with a speedometer, its speed reading would increase each second by about
10 m/s
Ten seconds after starting from rest, a freely-falling baseball will have a speed of about
100 m/s
Daisy weighs 120 N and carries Trixie who weighs 40 N on her back. The support force on Daisy's feet is
160
A 50-N object falling in air experiences 30 N of air resistance. The amount of net force on the falling object is
20
The average speed of a horse that gallops a distance of 10 km in a time of 30 min is
20 km/h
If a ball rolls down an inclined plane and gains 4 m/s each second it rolls, its acceleration is
4 m/s2
An 800-N man stands at rest with his weight evenly distributed on two bathroom scales. The reading on each scale is
400
When a 10-kg block is simultaneously pushed toward the east with 20 N and toward the west with 15 N, the combination of these forces on the block is
5 N east
An object is pulled with two forces, 10 N northward and 15 N southward. The magnitude of the net force is
5N
When a 10-N object is suspended at rest by two equally-taut vertical strands of rope, the tension in each strand is
5N
A 10-N falling object encounters 4 N of air resistance. The net force on it is
6
As an object freely falls, it's ______ increases.
Acceleration
An empty jug of weight W is at rest on a table. When water of weight w is poured into it, the amount of support force supplied by the table is
W + w.
You're at rest in a hammock when a hungry mosquito sees you as lunch, while a 2-m/s breeze is blowing. If the mosquito joins you for lunch, it should first hover over you by flying
against the breeze at 2 m/s
Which has zero acceleration?
all of the above
Given that two forces of 10 N and 15 N act horizontally (one dimension) on an object, the net force must
be either 5 N or 25 N
When sign painters Burl and Paul stand on opposite ends of a scaffold, the tensions in each of the two supporting ropes
depend on the relative weights of Burl and Paul.
Aristotle treated motion by
dividing it into two classes
When a crate slides down an incline at a constant velocity it is
dynamic equilibrium
Marie pushes horizontally on her desk, but not hard enough to get it moving. The friction force acting on the desk is
equal and opposite to her push
Burl and Paul on a sign-painting scaffold are in equilibrium, which means that the net upward supporting force of the vertical ropes is
equal and opposite to the combined weights of Burl, Paul, and the scaffold.
A motor scooter undergoes acceleration when it
gains speed, decreases speed, and changes direction
A glance at the speedometer on your vehicle will tell you your
instantaneous speed
When a ball increases in speed by the same amount each second, its acceleration
is constant
Whenever the net force on an object is zero, its acceleration
is zero
When Marie pushes her desk to the right, friction between the floor and the desk acts toward
left
A chunk of gold weighs 1 N on Earth. On the Moon its weight would be
less
A kilogram is a unit of
mass
Between mass and weight, the more fundamental quantity is
mass
The net force on an object is
the combination of all forces acting on it
Your weight is
the gravitational attraction between you and the earth
When you push a crate across a level floor at constant velocity, friction between the crate and the floor is
the same amount as your pushing force
Acceleration and velocity are
very different from each other
Acceleration and velocity are
very different from each others
Lift an object against the force of gravity if you want to judge its
weight
