Midterm Review Flashcards
As the distance between two bodies increases, the force of attraction between the bodies ________ .
A. decreases
The slope of a position versus time graph gives _______________________________.
average velocity
An accelerating object travels _________________
slower during each second that it moves AND farther during each second that it moves
Which encounters a greater force of air resistance, a falling elephant or a falling feather?
the feather
The best measure of an object’s inertia is its ____.
mass
The unit for power in the SI system is ____.
watt
An object with mass m is thrown straight up. At its highest point, the net force on it is
mg
What would the rate of speed of a man running 60 ft in 10 sec be?
6 ft/sec
A block with a mass of 10 kg is located 30 m above a road. If the block fell, what would be its kinetic energy at the moment it struck the road? (PE = KE) (PE=mass x accel. of gravity x height) (accel. of gravity = 9.8m/secSQUARED)
3000 joules
Efficiency of work is the ratio of work output to
work input
What is the force called with which the earth pulls on an object?
gravity
The transfer of energy by mechanical means is
work
A negative linear acceleration indicates that an eastward moving object is
slowing down
The ___ component(s) of a projectile’s velocity will change while the projectile is in the air.
vertical (Vy)
Which of the following is not a type of energy?
Potential Kinetic Heat Cold
Cold
A pendulum at the bottom of its swing is an example of ___ energy.
kinetic
A rock is thrown from a catapult at an angle of of 25 degrees above the horizontal with an initial velocity of 45 m/s. Find the horizontal and vertical components of the rock’s initial velocity
41m/s, 19 m/s
When an object is in motion it is said to have
kinetic energy
In what direction does friction act with respect to the motion of a sliding object?
in the opposite direction
A quantity that has both magnitude and direction is referred to as
vector
If you raised a physics book 5 m, it gains a certain amount of PE . However, if you raised another book (with the same mass) 10 m, its PE is
twice as much
The equation to find the weight of an object is
weight = mass x g
When a body is at rest, _____
all of the forces are in balance
Newton’s second law of motion tells us that as the force on an object increases, the acceleration
increases
A dog swims west across a river at 3.0 m/s relative to the river that flows north at 5.0 m/s. Find the magnitude and direction of the dog’s resultant velocity.
5.8m/s, 31 degrees W of N
You are standing n a moving bus, facing forward, and you suddenly fall backward. You can imply from this that the bus’s
velocity increased
An object weighing 40N on the earth’s surface would weigh only 10 N when its distance from the center of the earth is
doubled