physics midterm
What is the y-intercept of a line with the equation y = 6x -11 ?
-11
a projectiles vertical acceleration is always
-9.8m/s^2
Allen shoots a 3-pointer with an initial velocity of 2 m/s at an angle of 60 degrees. If it takes the ball 0.35 seconds to return to its starting height, what is the ball's range?
.35
A ball is thrown horizontally at a height of 2.2 meters at a velocity of 65 m/s. Assume no air resistance. How long until the ball reaches the ground?
.67 seconds
When an object is launched horizontally, what is the initial vertical velocity?
0 m/s^2
Bill runs 400 meters to Andy's house, turns around, and runs 400 meters back home. What is Bill's displacement?
0 meters
a projectiles horizontal acceleration is always
0m/s^2
A plane flying horizontally at 120 m/s drops a crate. When the crate strikes the ground 15 seconds later, what is the magnitude of the horizontal component of its velocity?
120
A 55 kg water skier is being pulled across the water with an acceleration of 2 m/s2 forward. The frictional force between the skis and the water is 15 N backwards. What is the magnitude of the force applied by the boat?
125 N forward
What is .00025A in Scientific Notation?
2.5 x 10-4 A
A pencil is dropped from a height of 35 meters. What is its velocity right before it hits the ground?
26.2 m/s
An object is dropped from some height and reaches the ground in 3 seconds. Which of the following is the object's velocity right before it hits the ground?
29.4
What is the slope of the line with the equation y = 3x + 5?
3
An 8kg box slides down a frictionless 24° ramp as shown. What is the x-component of gravity acting on the box?
31.9
A car accelerates from rest and travels 373 meters. If this took the car 12.50 seconds what was the car's acceleration?
4.77 m/s^2
How would you write 4.3756 x 104 in standard form?
43,756
A man wants to shoot an arrow so that it has the greatest range (horizontal distance). At what angle should he shoot the arrow?
45
A car starts 2 m east of the school and travels with a velocity of 15 m/s east for 3 seconds. Where does it end up?
47 m east
Forces/Newton's Laws: An 8kg box slides down a frictionless 24° ramp as shown. What is the normal force that the ramp exerts on the box?
71.6
Bill runs 400 meters to Andy's house, turns around, and runs 400 meters back home. What is Bill's distance?
800 meters
A train is moving at 7 m/s. It then accelerates at a rate of 1.93 \frac{m}{s^2}s2m and gets up to speed of 26 m/s. How long did this process take?
9.85 sec
dependent variable
The variable that changes as a result of changing the independent variable.
independent variable
The variable that is manipulated in an experiment.
the slope of a straight line on a Velocity v Time graph will be
acceleration
a free body diagram is used to
accurately represent forces acting on an object
At which of the following places does a projectile have the greatest acceleration?
all points have the same acceleration
according to newtons second law an objects net force is ______ in the ________ direction as its acceleration
always, same
If the line crosses over the the x-axis on a velocity v time graph the object
changes direction (turns around)
on a velocity time graph, the graph starts negative and crosses x axis to become positive, with a positive slope, what is happening
constant positive acceleration
normal fore (fn) requires
contact with a surface and is perpendicular to that surface
Suppose a particle is accelerated through space by a constant 10-N force. Suddenly the particle encounters a second force of 10-N in a direction opposite to that of the first force. The particle
continues at a speed it had when it encountered the second force
when an object has constant velocity, the position time graph will be a
diagonal (sloped) line
when the object is accelerating the velocity-time graph will be
diagonal (sloped) line
friction (ff) is always
directed opposite of an objects motion
Which of the following is represented by the area on a velocity vs. time graph?
displacement
the area between the curve and the x axis on a velocity v time graph will be the
displacement
vectors
displacement, velocity
scalars
distance, speed
the horizontal and vertical components of motion of a projectile _______ affect one another
do not
newtons third law
for every force, there is an opposite and equal force
when an object has constant velocity the velocity v time graph will be a
horizontal line
when the object is accelerating the acceleration-time graph will be
horizontal line
when an object has constant velocity the acceleration v time graph will be a
horizontal line at 0
velocity
how fast an object is moving and its direction. calculated by dividing displacement by time. (+ and - signal direction)
speed
how fast and object is moving. calculated by dividing distance by time
on a velocity time graph, the line starts at zero and goes negative, what is happening
increasing negative velocity
For a straight line on a position v time graph, the y intercept is the ___________, or _________ and the slope is __________
initial position, displacement, velocity
What effect does the mass of a projectile have on the time it's in the air? (Neglecting air resistance)
it has no effect
on a speed time graph, the line is straight positive, what is the object doing?
moving at a constant speed
on a speed time graph, the line is positive and moving towards zero (negative slope) what is happening
object is slowing down
newtons first law
objects in motion stay in motion and objects at rest will stay at rest until an outside net force acts upon it. (law of inertia)
if an object is slowing down, its acceleration points the _______ direction of its velocity
opposite
when the object is accelerating the position-time graph will be
parabolic (curved)
slope of the line can be found by
picking two coordinates and calculating rise/run
if an object is speeding up, its acceleration points the _______ direction of its velocity
same
If the line is moving towards the the x-axis on a velocity v time graph the object is
slowing down
If the line is moving away from the x-axis on a velocity v time graph the object is
speeding up
on a velocity time graph, the slope is negative and moving away from 0 (y values are 0 to negative), what is the object doing
speeding up
gravity (fg) is always
straight down
an objects net force is defined as the
sum of the individual forces acting on it
how do you find acceleration on a velocity time graph
take the slope
distance
the amount of ground covered
If I water the plant more often, then it will grow taller. Name the independent variable.
the amount of water
A ball is launched from rest in outer space. Assume all outside forces other than the launch force are negligible. Three seconds after the ball has been launched, which of the following is true?
the ball is not accelerating and moves with constant velocity
On a position vs. time graph, the steeper the slope _____.
the faster the speed
A car is driving on the road when a fly hits the window. In this situation:
the force exerted on the car by the fly is equal to the force exerted by the fly on the car
newtons second law
the net force applied to an object is the product of the mass and acceleration for that object. fnet=ma
An object is projected horizontally from a cliff. The time it takes to hit the ground is
the same amount of time than if it was just dropped
displacement
the shortest distance from an objects initial position to its final position. (+ and - signal direction)
ma=
the sum of the forces
An elevator is traveling upward in an elevator shaft at a constant speed. Assume that all friction effects are negligible. According to this situation, the forces on the elevator are best described by the following:
the upward force is equal to the downward force due. to gravity
Suppose a projectile is moving through the air as it goes up and back down. When the object is at its maximum height, what is something that is NOT true?
the vertical acceleration is 0 m/s^2
slope intercept form is
y = mx+b
