Phys Chapter 1 & 2 HW
Daisy weighs 120 N and carries trixie who weighs 40 N on her back. The support force on Daisy's feet is
160 N
Jake pulls on a 25 kg cart with a constant force of 50 N. what is the wagon's acceleration?
2.0 m/s squared
A 50-N object falling in air experiences 30 N of air resistance. The net force on a falling object is
20 N
The average speed of a horse that gallops a distance of 10 km in a time of 30 minutes is
20 km/h
When a ball increases in speeed by the same amount each second, its acceleration
is constant
According to Aristotle, a rolled ball eventually comes to a stop because
it seeks its natural state of rest.
A probe in space continues in its motion due to...
its own inertia.
Galileo said that if you rolled a ball along a level surface it would
keep rolling without slowing down if no friction acted upon it.
Aristotle believed that natural laws could be understood by
logic.
A kilogram is a unit of...
mass.
At the end of 1/2 second, an apple freely falling from rest has a speed of
more than 10m/s
A stone is thrown verticaly upward. At the top of its vertical path, the force acting on it is
only the force due to gravity
A hockey puck slides across a frozen pond. If ice friction and air resistance are neglected, the force needed to keep the puck sliding at constant velocity is
0 N
An object travels 8 m in the 1st second of travel, 8 m again during the 2nd second of travel, and 8 m again durign the 3rd second. Its acceleration is
0 m/s^2
If you toss a ball straight upward at 40 m/s with no air resistance, one second after it reaches the top of its path its speed is
10 m/s
The acceleration of a vertically thrown ball at the top of its path is
10 m/s
The gain in speed each second for a freely falling object is about
10 m/s
A push on a 1-kilogram brick accelerates the brick. Neglecting friction, to equally accelerate a 10-kilogram brick requires the force to be...
10 times as much.
A 10-kg mass at Earth's surface weighs about...
100 N.
Ten seconds after starting from rest, a freely falling baseball will have a speed of about
100 m/s
While in an airplane flying at 100 km/h you look down from the window and spot another airplane flying at the same speed in the opposite direction. Relative to you, the speed of the spotted plane is
200 km/h
Burl and Paulf have a total weight of 1300 N. The tensions in the ropes that support the scaffold they stand on add to 1700 N. The weight of the scaffold itself must be
400 N
The force of friction on a sliding object is 50 N. The applied force needed to maintian a constant velocity is
50 N
In a dream you're inn a car traveling at 50km/h and you bump into another car traveling toward you at 48km/h. The speed of impact is...
98 km.h
Compared with a 1-kg block of solid iron,, a 2-kg block of solid iron has the same...
All of the above 1. mass 2. weight 3. volume
The equilibrium rule, "E"F = 0, applies to
BOTH 1. objects or systems at rest. 2. objects or systems in uniform motion in a straight line.
If gravity between the Sun and Earth suddenly vanished, Earth would move in
a straight-line path
If the mass of an object does not change, a constant net force on the object produces constant
acceleration
Newton's second law focuses on
acceleration
When you stand at rest on a pair of bathroom scales, the readings on the scales will always
add to equal your weight
Which has zero acceleration?
all of the above 1. an object moving at constant speed 2. an object in mechanical equilibrium 3. an object at rest
A heavy object and a light object in a vacuum are dropped at the same time from rest. The heavy object reaches the ground
at the same time as the light object
A ball tossed vertically upward reaches its highest point and then falls back to its starting point. During this up-and-down motion the acceleration of the ball is always...
directed downward.
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.
When a crate slides down an incline at a constant velocity, it is
in dynamic equilibrium
If an object's mass decreases while a constant force acts on it, the acceleration
increases
If you jump straight up while inside a fast moving train that gains speed, you land
slightly behind your original position.
The resistive force of friction occurs for
solids, liquids, and gases
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
What did Galileo incorporate in his study of motion that Aristotle overlooked?
the role of time
A chunk of metal has a mas of 1 kg on Earth. If the same chunk were on the moon its mass would be
the same
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
Phil Physiker standing at the edge of a cliff throws one ball straight up and another ball straight down, both with the same speed. Both ball hit the ground at
the same speed in different time
As an object freely falls, its
velocity increases
An object in motion tends to remain in motion
without the need of a force
When a rock thrown straight up reaches the exact top of its path, its velocity is
zero and its acceleration is 10 m/s^2
The acceleration of a Tesla, that maintains a constant velocity of 120 km/h over a time of one-half hour, is
zero because of no change in velocity
The force required to maintain an object at a constant velocity in free space is equal to...
zero.