Physics test- Projectiles

If you throw a stone horizontally from the top of a cliff, one second after leaving your hand its vertical distance below the top of the cliff is...

5 m/s

a projectile is launched vertically upward at 50 m/s. When neglecting air drag its speed upon returning to its starting point is

50 m/s

a bullet is fired horizontally with an initial velocity of 300 m/s from a 20m high tower. if air resistance is negligible, the bullet hits downrange at about...

600m

acceleration in the y-direction is...

always negative (-10m/s²)

as soon as a ball rolls off the edge of a table...

it is not acted on by any horizontal forces

what is projectile motion?

motion in 2 dimensions, only influenced by gravity

Dr. Who projects a ball horizontally from a lab bench. The ball lands on a bullseye marked on the floor a horizontal distance equal to the ball's initial speed

multiplied by its time in the air

A player kicks a soccer ball in a high arc towards the opponent's goal. At the highest point in its trajectory

neither the ball's velocity nor its acceleration are zero

For general projectile motion with no air resistance, the horizontal component of a projectile's velocity

remains a non-zero constant

for general projectile motion with no air resistance, the verticle component of a projectile's acceleration

remains a non-zero constant

as soon as a bowling ball rolls off the edge of a table its horizontal component of velocity...

remains constant

while a rick thrown upward at 50 degrees to the horizontal rises, neglecting air drag, its horizontal component of velocity

remains unchanged

a ball is throw horizontally from the top of a tower at the same instant that a stone is dropped vertically. Which object is traveling faster when it hits the level ground below if neither of them experience air resistance?

the ball

Callie tosses a ball upward at an angle. Assuming no air resistance, which component of velocity changes with time?

the vertical component

the acceleration in the x direction is...

zero

an object in two-dimensional projectile motion with no air resistance, the horizontal acceleration is always...

zero, and the vertical acceleration is always a non-zero constant downward

a bullet fired horizontally over level ground hits the ground in .5 secins. if it had been fired with twice the speed it would have it the ground int

.5 seconds

work out on paper - a heavy rock is shot upward from the edge of a vertical cliff. It leaves the edge of the cliff with an initial velocity of 15 m/s directed 25 degrees from the vertical and experiences no air resistance. how high is the cliff?

1.26m

A ball player wishes to determine pitching speed by throwing a ball horizontally from an elevation 5m above ground level. The ball lands 20m downrange. The player's pitching speed is about...

20 m/s

a gun with a muzzle velocity of 100 m/s is fired horizontally from a tower. neglecting air resistance, how fat downrange will the bullet be 1 second later.

100 m

work out on paper - A girl throws a rick horizontally with a velocity of 10 m/s from a bridge. It falls 20m to the water below. how far does the rock travel horizontally before striking the water?

20m

work out on paper - A player hits a tennis ball into the air with an initial velocity of 32 m/s at 35 degrees from the vertical. How fast is the ball moving at the highest point on its trajectory?

26 m/s

work out on paper - you throw a rock horizontally off of a cliff with a speed of 20 m/s. after 2 seconds, the magnitude of the velocity of the rock is closest to...

28 m/s

two projectiles are fired from ground level at equal speeds but different angles. One is fired at an angle of 30 degrees and the other at 60 degrees. Neglecting air resistance, the projectile to hit the ground first will be the one fired at...

30 degrees

work out on paper - A boy kicks a football from ground level with an initial velocity of 20 m/s at an angle of 30 degrees above the horizontal. What is the horizontal distance to the point where the football hits the ground if we neglect air resistance?

35m

work out on paper - a ball is thrown at an original speed of 8 m/s at an angle of 35 degrees above the horizontal. If there is no air resistance, what it the speed of the ball when it returns to the same horizontal?

8 m/s

work out on paper - A ball thrown horizontally from a point 24 m above the ground, strikes the ground after traveling horizontally a distance of 18m. With what speed was it thrown?

8.1 m/s

a projective is launched from ground level at 15 degrees above the horizontal and lands downrange. What other projection angle for the same speed would produce the same down-rang distance?

90-15 = 75 degrees

a projectile is fired into the air at an angle of 50 degrees above ground level and hits a target downrange. it will also hit the target it fired at an angle of...

90-50 = 40

work out on paper - A stone is thrown horizontally with an initial speed of 10 m/s from the edge of a cliff. A stopwatch measures the stone's trajectory time from the top of the cliff to the bottom to be 4.3s. what is the height of the cliff if air resistance is negligible?

91 m

work out on paper - a shell is launched with a velocity of 100 m/s at an angle of 30 degrees above horizontal from a point on a cliff 50m above a level plain below. How far from the base of the cliff does the shell strike the ground

963m

Mary and Debra stand on a snow covered roof. They both throw snowballs with the same initial speed, but in different directions. Mary throws her snowball downward, at 30 degrees below the horizontal; Debra throws her snowball upward, at 30 degrees above the horizontal. Which of the following statements are true about just as the snowballs reach the ground below?

Debra's snowball will stay in the air longer than Mary's

A rock is thrown from the upper edge of a tall cliff at some angle above the horizontal. It reaches its highest point and starts falling down. Which of the following statements about the rock's motion are true just before it hits the ground?

Its horizontal velocity component is the same as it was just as it was launched.

James and John dive from an overhang into the lake below. James simply drops straight down from the edge. John takes a running start and jumps with an initial horizontal velocity of 25 m/s. If there is no air resistance, when they reach the lake below, the splash down speed of...

John is larger than that of James

Mary and Debra stand on a snow covered roof. They both throw snowballs with the same initial speed, but in different directions. Mary throws her snowball downward, at 30 degrees below the horizontal; Debra throws her snowball upward, at 30 degrees above the horizontal. Which of the following statements are true about just as the snowballs reach the ground below?

Mary's snowball will hit the ground before Debra's

a dropped ball gains speed because

a gravitational force acts on it

work out on paper - A marble moving 1.48 m/s rolls off the top edge of a 125cm high table a. how far from the base of the table will it strike the floor b. how long will it be in the air

a. 75 m b. 0.505 seconds

a pilot drops a package from a plane flying horizontally at a constant speed. neglecting air resistance, when the package hits the ground the horizontal location of the plane will

be directly over the package

a ball rolls off the edge of a table at the same tome another ball drops vertically from the same table. The ball to hit the floor first is the

both will hit at the same time

while a rock thrown upward at 50 degrees to the horizontal rises, neglecting air drag, its vertical component of velocity

decreases

while an airplane flies at 40m/s at an altitude of 500 meters, the pilot drops a heavy package that falls to the ground. Neglecting air drag, about where does the package land relative to the plane flying above?

directly below the plane

a ball upward. Neglecting air drag, the acceleration along its path is...

g downnward

for general projectile motion with no air resistance, the horizontal component of a projectile's acceleration

is always zero

in an air-free chamber, a pebble is thrown horizontally, and at the same instant a second pebble is dropped from the same height. Compare the times of fall of the two pebbles

the hit the ground at the same time

a hunter on level ground fires a bullet at an angle of 10 degrees below the horizontal while simultaneously dropping another bullet from the level of the rifle. which bullet will hit the ground first?

the one fired

a hunter on level ground fires a bullet at an angle of 10 degrees above the horizontal while simultaneously dropping another bullet from the level of the rifle. which bullet will hit the ground first?

the onedropped

Dr. Who projects a ball horizontally from a lab bench. The ball lands on a bullseye marked on the floor a horizontal distance away. Compared to the time for the ball to simply drop vertically from the bench, the time in the air for Dr. Who's projected ball is...

the same

an object is dropped and freely falls to the ground with acceleration g. If it is thrown upward at an angle instead, neglecting air drag, the acceleration along its path will be...

the same

dr. chuck projects a ball horizontally from a lab bench. If the projection speed of the ball were greater, the time in the air would be

the same

after a rock thrown straight up reaches the top of its path and then falls a short distance, its acceleration is (neglecting air resistance)

the same as at the top of its path