physics 9/30

For a projectile, which of the following quantities is CONSTANT throughout the trajectory?

• y-component of velocity

• x-component of velocity

• y-component of position

• x-component of position

A ball rolls off a table top and strikes the floor as shown. Given the measurements made, the time the projectile spent in the air is ---.

• 17 s

• 0.34 s

• 0.58 s

• 0.49 s

A ball rolls off a table and strikes the floor, as shown. If the time the ball spent in the air was 0.58 s, how fast did the ball leave the table?

• 3.6 m/s

• 1.2 m/s

• 2.9 m/s

• 0.99 m/s

A skateboarder rolls off a bridge into the river as shown. If the skateboarder was originally moving at 7.0 m/s, how much time did the skateboarder spend in the air?

• 1.3 s

• 0.79 s

• 38.5 s

• 0.70 s

• Not enough information given.

An object is thrown at an angle of 30°. What angle does the object need to be thrown at to travel the greatest distance?

• 30°

• 45°

• 50°

• 65°

Two rocks with different size and mass are dropped from the same height. Which of the rock will reach the ground first?

• greater rock

• smaller rock

• both reach the ground at the same time

At what point is v_y= 0 m/s?

• A

• B

• C

• D

• None of these points

What is the horizontal acceleration of a projectile?

An object is thrown at an angle of 50°. What change needs to occur for the object to travel the farthest?

• Decrease angle by 5°.

• Increase the angle by 5°.

• Increase the angle by 10°.

• Decrease the angle by 10°.

At what point does the object have a decreasing vertical velocity?

• A

• B

• C

• D