Physics 1D-2D concepts
A ball is thrown straight up. At the top of its path its speed at that moment (instantaneous speed) is
0 m/s
A train travels 6 meters in the first second of travel, 6 meters again during the second second of travel, and 6 meters again during the third second. Its acceleration is
0 m/s
The horizontal acceleration of any projectile (neglecting air resistance) is
0 m/s
A freely falling object starts from rest. After falling for 1 second, it will have a speed of about
10m/s
A freely falling object starts from rest. After falling for 3 seconds, it will have a speed of about
30m/s
A ball is thrown downward with an initial velocity of 7.0 m/s. How fast was it going exactly 3.5 s into its fall?
41 m/s
In the absence of air resistance, the angle at which a thrown ball will go the farthest is
45
A boat is traveling across a river with a speed of 4.5 m/s. If the river current is 2.2 m/s, calculate the magnitude of the boat's velocity from the perspective of an observer on the river bank.
5.0 m/s
If a projectile is fired straight up at a speed of 30 m/s, the total time to return to its starting point is about
6 seconds
A cannonball is launched horizontally from a tower. If the cannon has a barrel velocity of 60 m/s, where will the cannonball be 1 second later? (Neglect air resistance.)
60m downrange
A car starts from rest and after 7 seconds it is moving at 42 m/s. What is the car's average acceleration?
6m/s
A boat is moving forward at 15 m/s against a river current of 10 m/s. Uing this as an example of vector addition, which of the following is true?
A stationary on the river bank will think the boat is going 5m/s.
In the absence of air friction, the horizontal component of a projectile's velocity doesn't change as the projectile moves.
Always true
If an object moves with positive velocity experiences a constant negative acceleration, the object will:
speed up
In the falling object equations, "g" stands for
the acceleration due to gravity in m/s/s
A vector is a quantity that has
Direction and magnitude
Aristotle described the the natural state of terrestiral objects as
at rest
At what part of a path does a projectile have minimum speed?
at the top of its path
A ball is thrown upwards and caught when it comes back down. In the absence of air resistance, the speed of the ball when caught would be
the same as the speed it had when thrown upwards
After a rock that is thrown straight up reaches the top of its path and it starting to fall back down, its acceleration is (neglecting air resistance)
the same as when it was at the top of its path
Accelerations are produced by
forces
An object is dropped and falls freely to the ground with an acceleration of g. If it is thrown upward at an angle instead, its acceleration would be
g downward
The first person to establish the idea that all objects, reagrdless of mass, will fall at the same rate was
galileo
When you look at the speedometer in a moving car, you can see the car's
instantaneous speed
When a basketball player jumps to make a shot, once the feet are off the floor, the jumper's acceleration
is g; more more, no less
a projectile is fired horizontally in a vacuum. The projectile maintains its horizontal component of speed because it
is not acted on by any horizontal forces
A projectile is fired horizontally in a vacuum. The projectile maintains its horizontal component of speed because it
is not acted on by any horizontal forces.
If a ball were equipped with a speedometer and allowed to fall freely on a planet where the acceleration due to gravity is 23 m/s2, the reading on the speedometer would increase each second by
23 m/s
A ball is thrown at an angle of 38 to the horizontal. What happens to the magnitude of the balls vertical acceleration during the total time interval that the ball is in the air?
It remains the same
A scalar is a quantity that has
Magnitude
At the instant a ball is thrown horizontally with a large force, an identical ball is dropped from the same height. Which ball hits the ground first?
Neither. Both hit ground at same time
The horizontal component of a projectile's velocity is independent of
The vertical component of its velocity
Suppose an object is dropped and is in free fall. With each passing second, the object falls
a larger distance than in the second before
A ball is thrown straight up. At the top of its path its acceleration is
about 10 m/s
If a freely falling object were somehow equipped with a speedometer, its speed reading would increase each second by
about 10m/s
A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. During this time the acceleration of the ball is always
directed downward
A ball is thrown into the air at some angle. the moment it reaches the top of its trajectory, its velocity is
equal to the initial horizontal component
Which of the following is NOT considered a positive direction?
west