Physics - Chapter 4
A model airplane traveling north at 4 km/h in a 3-km/h crosswind (at right angles) has a ground speed of
5 km/h
Toss a ball straight up in the air at 30 m/s and without air resistance its speed will again be 30 m/s in
6 seconds
A ball tossed at an initial angle of 25° will have the same range as a ball tossed at the same speed at which of the following angles?
65 degrees
A motorcycle undergoes acceleration when
A nonzero net force acts on it
If action is a foot kicking a soccer ball, the reaction is an equal force on the
foot
An object with a mass of 1 kilogram on Earth (1)
has the same mass on the moon
When you slide a coin against another coin at the edge of a table, both coins will
hit the floor at the same time
A ball thrown off a cliff will fall 5 meters below its original straight-line trajectory when it is thrown
horizontally
When you jump vertically upward, strictly speaking, you cause earth to
move downward
In the absence of air resistance, the horizontal component of velocity for a baseball tossed across a field
not changed
The pressure that your book exerts against a tabletop is greater when you place it(on it's side, on it's back or on it's corner.
on it's corner
A cart is pushed and undergoes a certain acceleration. If the force is held constant and the mass of the cart doubles, its acceleration would be
one-half
If a 10-kg rock and 5-kg rock are dropped from the same height, at the same time, and in the absence of air resistance, then they will fall
same acceleration
When you toss a rock straight upward, which is no longer present at the top of its path?
speed
what is a vector quantity?
speed and direction
A boulder falls due to gravity. The reaction to the force on the boulder is
the boulder pulling up on Earth
You are standing at rest and begin to walk forward. What force pushes you forward?
the force of the ground on your feet
The reason a 10-kg rock falls no faster than a 5-kg rock in free fall is that
the force/mass ratio is the same for both
The force that propels a heavy truck along a highway is provided by
the highway pushing back on the wheels of the truck
A cart is pushed and undergoes a certain acceleration. It it were pushed with twice the force while its mass doubles, its acceleration would be
the same
Earth pulls on the Moon with a certain force. Relative to this force, the pull of the moon on earth is
the same
When a net force acts on an object, its acceleration depends n the object's
mass
When no air resistance acts on a projectile, its horizontal acceleration is
0
Use Newton's second law to answer this question: The acceleration of a vertically thrown ball at the top of its path is
10 m/s/s
Use Newton's second law to answer this question: The acceleration of a vertically thrown ball at the top of its path is
10 m/s2
The force of gravity acting on a 2-kg melon is
20 N
Each of the weight .....
40/ 9 m/s2
A projectile has equal horizontal and vertical components when it travels at
45 degrees
An elevator is being lifted at a constant speed by a steel cable attached to an electric motor. There is no air resistance, nor is there any friction between the elevator and the walls of the elevator shaft.
Equal to the force of gravity
In a force diagram .....
N
If a constant net force to the right is applied to a couch on a frictionless surface
The couch will have a constant acceleration to the right
A horse is hitched to a wagon. Which statement is correct?
The force that the horse exerts on the wagon is just as strong as the force that the wagon exerts on the horse.
A lead-filled tennis ball and a regular tennis ball are dropped from the top of a tall building at the same time. Air drag does affect motion. Which reaches the ground first?
The lead-filled one
A Kitten and a tiger .....
Tiger
A kitten and a tiger .....
Tiger
The force of air friction (air drag) against a falling sack of potatoes
acts upward. increases with increased area. increases with increased speed
When your mass increases, your weight
also increases
The amount of air resistance that acts on a wingsuit flyer (and a flying squirrel) depends on the flyer's
area and speed
A math book and a physics book are tied together with a length of string. With the string taut, one book is pushed off the edge of a table. As it falls, the other book is dragged horizontally across the table surface. With no friction, acceleration of the books is
between 0 and gravity
In free fall, the net force is .....
constant
Newton's concept of motion said that the natural state of an object was
constant velocity
As mass is added to a pushed object, its acceleration
decreases
In the absence of air resistance, the vertical component of velocity for a baseball tossed across a field
decreases then increases
When no air resistance acts on a fast-moving baseball, its acceleration is
downward gravity
When a squid pushes against water, the squid moves forward because the water
exerts a net forward force
Relative to the ground, an airplane gains speed when it encounters wind from behind, and loses speed when it encounters wind head-on. When it encounters wind at a right angle to the direction it is pointing, its speed relative to the ground below
increases
When you increase the net force on a shopping cart its acceleration
increases
During each second of free fall, the speed of an object
increases by the same amount
Mass is most closely related to
inertia
For a given force, acceleration and mass are
inversely proportional to each other
Whenever one object exerts a force on a second object, the second object exerts a force on the first that
is opposite in direction, is equal in magnitude, occurs at the same time.
An object will accelerate when
it is pushed or pulled with a net force
When we say that 1 kilogram weighs 10 N, we mean that
it's true at Earth's surface
A tennis ball filled with lead and a regular tennis ball are dropped from the top of a tall building at the same time. Both encounter air resistance. Which reaches the ground first?
lead-filled
A lead-filled tennis ball and a regular tennis ball are dropped from the top of a tall building. Air drag does affect motion. The ball that experiences the greater amount of air drag is the
lead-filled one
A 20-N object falling with 5 N of air resistance has an acceleration (less than,greater than or equal to gravity)
less than gravity
Air resistance on a projectile has no effect on its
mass
A force is a push or pull that is required to change the
the state of motion of an object
The component of velocity that changes for a projectile in the absence of air resistance is
vertical
An object with a mass of 1 kilogram on Earth (2)
weighs less on the moon
The force of friction between two surfaces can act
whether or not the surfaces move relative to each other
For a pair of vectors at right angles to each other, the resultant
will be larger