Physics: Test #1

a laser is thrown upward with a speed of 12 m/s on the surface of planet X where the acc due to gravity is 1.5 m/s2 and there is no atmosphere. what is the max height reached by the laser

48 m

a bullet shot straight up returns to its starting point in 10s, what is the initial speed of the bullet, assuming negligible air resistance

49 m/s

when a ball is thrown straight up with no air resistance, the acceleration at its highest point.

is downward.

an object moving in the +X direction experiences an acceleration of +2.0 m/s^2. this means the object...

is increasing its velocity by 2.0 m in every second.

a ball is throw downward in the absence of air resistance. after it has been released, which statements concerning its acceleration is correct.

its acc is constant.

Suppose that a car traveling to the west begins to slow down as it approaches a traffic light. Which of the following statements about its acceleration is correct?

its acceleration is positive.

a ball is thrown straight up, reaches a maximum height, then falls to its initial height. which of the following statements about the direction of the velocity and acc of the ball as it is going up is correct?

its velocity points upward and its acceleration point downward.

if the velocity v time graph of an object is a straight line making an angle of +30 (counter clockwise) with the time axis, the object is

moving with constant non zero acceleration.

if the velocity v time graph of an object is a horizontal line, the object is

moving with zero acceleration

a jet plane is launched from a catapult on an aircraft carrier. in 2.0 s it reaches a speed of 42 m/s at the end of the catapult. assuming the acc is constant, how far did it travel during those 2.0 s

42 m

a car travels at 15 m/s for 10s. it then speeds up with a constant acc of 2.0 m/s2 for 15s. at the end of this time, what is its velocity?

45 m/s

an astronaut on a strange new planet having no atmosphere finds that she can jump up to a max height of 27 m when her initial upward speed is 6.0 m/s. what is the magnitude of the acc due to gravity on the planet

0.67 m/s2

at 1.0 s at 3.0 s

10 m/s2 0 m/s2

a cart starts from rest and accelerates uniformly at 4.0 m/s2 for 5.0 s. it next maintains the velocity it has reached for 10s. then it slows down at a steady rate of 2.0 m/s2 for 4.0 s. what is the final speed of the car?

12 m/s

an instrument is thrown upward with a speed of 15 m/s on the surface of planet X where the acc due to gravity is 2.5 m/s2 and there is no atmosphere. how long does it take for the instrument to return to where it was thrown.

12 s

a hammer is thrown upward with a speed of 14 m/s on the surface of planet X where the acc due to gravity is 3.5 m/s2 and there is no atmosphere. what is the speed of the hammer after 8.0 s

14 m/s

a water rocket can reach a speed of 75 m/s in 0.050 seconds from launch. what is its average acc?

1500 m/s2

from t = 0s to t = 5.0s from t = 0s to t = 8.0s

2.0 m/s2 -2.5 m/s2

a stone is thrown with an initial upward velocity of 7.0 m/s and experiences negligible air resistance. if we take upward as the positive direction, what is the velocity of the stone after 0.50 s?

2.1 m/s

to determine the height of a bridge above the water, a person drops a stone and measures the time it takes for it to hit the water. if the time is 2.3 s, what is the height of the bridge (neglect air resistance).

26 m

starting from rest, a dragster travels a straight 1/4 mi racetrack in 6.70 s with constant acc/ what is the velocity when it crosses the finish line

269 mi/h

a racquetball strikes a wall with a speed of 30 m/s and rebounds in the opposite direction w/ a speed of 26 m/s. what is the average acceleration of the ball during the collision with the ball?

2800 m/s2

an airplane increases its speed at the average rate of 15 m/s2. how much time does it take to increase its speed from 100 m/s to 160 m/s.

4.0 s

a cart with an initial velocity of 5.0 m/s to the right experiences a constant acc of 2.0 m/s2 to the right, what is the carts displacement during the first 6.0 s of this motion?

66 m

a ball is thrown downward from the top of a building with an initial speed of 25 m/s, it strikes the ground after 2.0 s, how high is the building (assuming negligible air resistance).

70 m

a laser is thrown upward with a speed of 12 m/s on the surface of planet X where the acc due to gravity is 1.5 m/s2 and there is no atmosphere. how long does it take for the laser to reach the max height

8.0 s

an airplane starts from rest and accelerates at a constant 10.8 m/s2. what is its speed at the end of a 400 m long runway

93.0 m/s

if the acceleration of an object is zero, then that object cannot be moving.

FALSE

if the velocity of an object is zero at some point, then its acceleration must also be zero at that point.

FALSE

an object is moving with constant non-zero acc in the +x direction. the position v time graph of this object...

a parabolic curve

an object is moving with constant non-zero acc in the +x direction. the velocity v time graph of the object is...

a straight line making an angle w the time axis

the slope of a velocity v time graph gives

acceleration

which of the following situations is impossible?

an object has constant non-zero velocity and changing acceleration.

human reaction time is usually greater than 0.10 s. if your friend holds a ruler between your fingers and releases it without warning, how far can you expect the ruler to fall before you catch it, assuming negligible air resistance

at least 4.9 cm

if the position v time graph of an object is a horizontal line, the object is

at rest

suppose a ball is thrown straight up and experiences no appreciable air resistance. what is its acceleration just before it reaches its highest point?

exactly g

two objects are dropped from a bridge, an interval of 1.0 s apart. air resistance is negligible. during the time that both objects continue to fall, their separation

increases

a rock from a volcanic eruption is launched straight up into the air with no appreciable air resistance. which one of the following statements about this rock while it is in the air is correct?

the acc is downward at all points in the motion except that is zero at the highest point.

if the velocity of an object is zero at one instant, what is true about the acceleration of that object?

the acceleration could be positive.

suppose that an object is moving with a constant velocity. which statement concerning its acceleration must be correct.

the acceleration is equal to zero.

suppose that a car traveling to the west begins to slow down as it approaches a traffic light. Which of the following statements about its acceleration is correct?

the acceleration is towards the east.

A brick is dropped from the top of a building. brick B is thrown straight down from the same building. They are released at the same time. Neglect air resistance. Compare the accelerations of the two bricks.

the two bricks have exactly the same acceleration.

two objects are thrown from the top of a tall building. one is thrown up, and the other is thrown down, both with the same initial speed.

they are traveling at the same speed.

the slope of a position v time graph gives

velocity