Physics

A projectile launched horizontally hits the ground in 0.8 s. If it had been launched with a much higher speed in the same direction, it would have hit the ground (neglecting Earth's curvature and air resistance) in... More than 0.8 s Less than 0.8 s 0.8 s

0.8 s

A ball is thrown straight upward at 10 m/s. Ideally (no air resistance), the ball will return to the thrower's hand with a speed of...

10 m/s

A snowball rolls off the edge of a horizontal roof at a velocity of 3.0 m/s. What is the speed of the snowball, 1 second later?

10.44 m/s

At what launch angle will a ball travel the farthest distance in a vacuum?

45 degrees

A cannonball is fired at some angle into the air. In the first second it moves 5 meters horizontally. Assuming it doesn't hit the ground and air resistance is negligible, how far does it move horizontally in the next second? More than 5 m Less than 5 m 5 m

5 m

A package falls out of a helicopter that is traveling horizontally at 70 m/s. It falls into the water below 8.0 seconds later. Assuming no air resistance, what is the horizontal distance it travels while falling?

560 m

A baseball is hurled into the air at an angle of 30 degrees above the horizontal and lands on a target that is at the same level as that where the baseball started. The baseball will also land on the target if it is thrown at an angle of ____ degrees.

60 degrees

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

60 m downrange

A cannon with a barrel velocity of 140 m/s launches a cannonball horizontally from a tower. Neglecting air resistance, how far vertically will the cannonball have fallen after 4 seconds?

80 m

Tommy is playing a carnival game for which he must throw a football through a hoop in order to win. If the hoop is located a horizontal distance of 0.8 m from Tommy, and Tommy throws the ball with a speed of 20 m/s, taking 0.5 s to reach the hoop, at what angle must Tommy make his throw to win? (the hoop is located at the point of maximum height for the football)

85.4 degrees

What is the resultant of a 3 unit vector and a 4 unit vector at right angles to each other (magnitude only)?

A 5 unit vector

A ball is thrown into the air at some angle. At the very top of its path, its velocity is Entirely vertical There's not enough information Both vertical and horizontal Entirely horizontal

Entirely horizontal

True or False: You throw a baseball at an upward angle into the air. The vertical distance between the baseball and an imaginary line tracing the upward angle into infinity is greater than the vertical distance the baseball would fall if it were dropped from rest and had been falling for the same amount of time.

False

The horizontal and vertical components of a projectile's motion are _____

Independent

A projectile is fired horizontally in a vacuum. The projectile maintains its horizontal component of speed because it Has no vertical component of speed to begin with Is not acted on by any forces The net force acting on it is zero Is not acted on by any horizontal forces

Is not acted on by any horizontal forces (d)

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 - they both hit the ground at the same time

In Chapter 2, you learned about "hang time", the time a jumper's feet are off the ground in a vertical jump. If the jumper runs horizontally and has the same vertical component of takeoff velocity, hang time will be... No different Decreased Increased

No different

Jose can jump vertically 1 meter from his skateboard when it is at rest. When the skateboard is moving horizontally, Jose can jump No higher higher

No higher

Helene the high jumper leaves the ground with a speed of 9.1 m/s at an angle of 75 degrees to the horizontal. If the bar is set at 4 m, does Helene clear the bar? (you need to tell me how high she jumps along with if she clears the bar or not)

No, y=3.86 m

After a rock that is thrown straight up reaches the top of its path and is starting to fall back down, its acceleration is (neglecting air resistance)

The same as it was at the top

Kyle throws a ball horizontally from the top of a building that is 5.0 m high. He hopes the ball will reach a swimming pool that is at the bottom of the building, 12.0 m horizontally from the edge of the building. If the ball is to reach the pool, with what initial speed must Kyle throw it with?

12.0 m/s

In the absence of air resistance, at what other angle will a thrown ball go the same distance as one thrown at an angle of 75 degrees?

15 degrees

A ball is thrown horizontally from the top of a tall cliff. Neglecting air drag, what vertical distance has the ball fallen 2.0 s later?

20 m

A cannonball is launched from the ground at an angle of 30 degrees above the horizontal and a speed of 30 m/s. Ideally (no air resistance) the ball will land on the ground with a speed of?

30 m/s

A projectile shot with an initial velocity of 51 m/s at an angle of 45 degrees follows a parabolic path and hits a stationary balloon at the top of its trajectory. With what speed does the projectile hit the balloon

36 m/s

A ball thrown in the air will never go as far as physics ideally would predict because... One can never throw the ball fast enough Gravity is acting Air friction slows the ball Ideally the ball would never land

Air friction slows the ball

At what part of a path does a projectile have minimum speed?

At the top of its path

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... O Larger than g g upward g downward None of the above

g downward