Physics Chapter 3 Test Part 1

At what angle should a water-gun be aimed in order for the water to land with the greatest horizontal range?

45 degrees

A stone is thrown horizontally from the top of a cliff. One second after it has left your hand, its vertical distance below the top of the cliff is

5 m

Ignoring air resistance, the horizontal component of a projectile's velocity

remains constant

Which of the following is not a vector quantity?

speed

A ball is thrown with a velocity of 20 m/s at an angle of 60 degrees above the horizontal. What is the horizontal component of its instantaneous velocity at the exact top of its trajectory?

10 m/s

A boat, whose speed in still water is 8.0 m/s, is directed across a river with a current of 6.0 m/s. What is the speed of the boat as it crosses the river?

10.0 m/s

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

100

An airplane travels at 141 km/h toward the northeast. What is its component of velocity due north?

100 km/h

A plane flying horizontally at a speed of 50.0 m/s and at an elevation of 160 m drops a package. Two seconds later it drops a second package. How far apart will the two packages land on the ground?

100 m

An airplane that flies at 100 km/h in a 100 km/h hurricane crosswind has a ground speed of

141 km/h

The resultant of two vectors is the smallest when the angle between them is

180 degrees

An object is dropped and freely falls to the ground with an acceleration of 1 g. If it is thrown upward at an angle instead, its acceleration will be

1g downward

A fighter plane moving 200 m/s horizontally fires a projectile with speed 50.0 m/s in a forward direction 30.0 degrees below the horizontal. What is the speed of the projectile with respect to a stationary observer on the ground?

245 m/s

Am Olympic athlete throws a javelin at four different angles above the horizontal, each with the same speed: 30 degrees, 40 degrees, 60 degrees, and 80 degrees. Which two throws cause the javelin to land the same distance away?

30 and 60 degrees

On a calm day, you can run a 1500-m race at a velocity of 4.0 m/s. If you ran the same race on a day when you had a constant headwind which slows your speed by 2.0 m/s, the time it would take you to finish would be

750 s

A ball is thrown at an original speed of 8.0 m/s at an angle of 35 degrees above the horizontal. What is the speed of the ball when it returns to the same horizontal level?

8.0 m/s

A soccer ball is kicked with a velocity of 25 m/s at an angle of 45 degrees above the horizontal. What is the vertical component of its acceleration as it travels along its trajectory?

9.80 m/s2 downward

A child wishes to determine the speed a slingshot imparts to a rock. How can this be done using only a meter stick, a rock, and a sling shot?

Launch the rock with a horizontal velocity from a height of 4.9 m. Use the equation y=vt+1/2gt^2 with initial velocity 0 m/s and solve for time. Use this time and the horizontal distance measured by the meter stick to find the x velocity using x=vt.

A large ship is traveling forward at a speed of 5.0 m/s relative to the water, due south. A passenger on the ship is walking towards the back of the ship at a speed of 1.5 m/s. a) What is the velocity of the passenger relative to the ship? b) What is the velocity of the passenger relative to the water?

a) 1.5 m/s (passangers given velocity) b) 3.5 m/s (passangers - boats)

Two cannonballs, A and B, are fired from the ground with identical initial speeds, but angle A is larger than angle B. a) Which cannonball reaches higher elevation? b) Which cannonball is in the air longer? c) Which cannonball travels further?

a) One whose angle is closer to 90 degrees b) One whose angle is closer to 90 degrees c) One whose angle is closer to 45 degrees

A pilot drops a bomb from a plane flying horizontally at a constant velocity. Neglecting air resistance, when the bomb hits the ground the horizontal location of the plane will

be over the bomb

Two displacement vectors have magnitudes of 5.0 m and 7.0 m, respectively. When these two vectors are added, the magnitude of the sum

could be as small as 2.0 m, or as large as 12 m

A rock is thrown upward at 50 degrees with respect to the horizontal. As it rises, neglecting air drag, its vertical component of velocity

decreases

You are throwing a ball for the second time. If the ball leaves your hand with twice the velocity it had on your first throw, its horizontal range R would be

four times as much

Ignoring air resistance, the horizontal component of a projectile's acceleration

is zero

A stone is thrown horizontally from the top of a tower at the same instant a ball is dropped vertically. Which object is traveling faster when it hits the level ground below?

the stone

A bullet is fired horizontally, and at the same instant a second bullet is dropped from the same height. Ignore air resistance. Compare the times of fall of the two bullets.

they hit at the same time.

Which one of the following is an example of a vector quantity?

velocity