Speed, Acceleration, and Gravity Test

A roller coaster car is traveling 1 m/s at the top of the track. At the bottom of the track, 5 seconds later, it is traveling 36 m/s. What is its average acceleration? Show your work. Delta Symbol= ∆

(a)  

A group of students were experimenting with how size, mass, and shape affect how fast objects fall. Two pieces of paper that are the same size and mass are dropped at the same time from the top of the ladder. One is flat and the other crumpled into a ball. Which piece of paper will hit the ground first? Choose the one best answer

• ❍ A The crumpled ball of paper will hit the ground first.
• ❍ B The smooth, flat piece of paper will hit the ground first.
• ❍ C Both pieces of paper will hit the ground at the same time.
• ❍ D More information is needed to determine which ball will hit the ground first.

Which of the following is the best explanation for why the crumpled ball of paper will hit the ground first?

• The crumpled paper will fall faster because there
  is less air resistance from the surface slowing its
  motion.

• The crumpled paper will fall faster because there
  is less gravity acting on it from the surface slowing its
  motion.

Two balls that look exactly the same but have different masses are dropped at the same time from the top of the ladder. Which ball will hit the ground first? (Choose the one best answer)

• ❍ F The ball with more mass will hit the ground first.
• ❍ G The ball with less mass will hit the ground first.
• ❍ H Both balls will hit the ground at the same time.
• ❍ J More information is needed to determine which ball has more kinetic energy

If two balls that look exactly the same but have different masses are dropped at the same time from the top of the ladder, what would be the best explanation for what we will observe?"

• The balls should not fall at the same rate even if they
  have different masses because the acceleration of
  gravity is different for each object.

• The balls should fall at the same rate even if they
  have different masses because the acceleration of
  gravity is constant.

Which equation would you use to find the acceleration of an automobile whose speed decreases from 48 m/s to 4 m/s in 11 seconds? (Choose the one best answer.)

• ❍ A (48 m/s – 4 m/s) / 11 s = 4 m/s2
• ❍ B (48 m/s + 4 m/s ) / 11 s = 4.7 m/s2
• ❍ C (4 m/s – 48 m/s) = - 44 m/s
• ❍ D (4 m/s – 48 m/s) / 11 s = - 4 m/s2

A group of students are walking at a speed of 2 m/s. Which row of data indicates their position at each second? (Mark the one best answer.)

• A
• B
• C
• D

Two students noted that the acceleration of a car was - 40 km/s2 . The first student said, “That can’t be right. You can’t have a negative acceleration.” The second student said, “That can’t be right. You can’t have s2 .” What would you say to each student to help them better understand how acceleration is described?

• Student 1, you can't have a negative acceleration. It
  means that the car’s speed is decreasing.
  Student 2, the s2 comes from km per s (speed) divided
  by time (s). km/s/s = km/s2

• Student 1, you can have a negative acceleration. It
  means that the car’s speed is decreasing.
  Student 2, the s2 comes from km per s (speed) divided
  by time (s). km/s/s = km/s2

  Two students made a video recording of a basketball as it was dropped. They recorded the time and position of the basketball at each frame. They made this data table based on the first eight frames of the recording. In 8 frames, the basketball traveled 20.4 cm. Use the data table to answer the questions.  Choose True if the statement is true; choose False if the statement is false. _____ The acceleration the students calculated for the ball for each time interval is not constant.

• True

• False

  Two students made a video recording of a basketball as it was dropped. They recorded the time and position of the basketball at each frame. They made this data table based on the first eight frames of the recording. In 8 frames, the basketball traveled 20.4 cm. Use the data table to answer the questions.  Choose True if the statement is true; choose False if the statement is false. _____ You would expect to see a pattern in which acceleration increases with each frame.

• True

• False