The world's fastest mammal
- Dashboard
- The world's fastest mammal
Most Recent Score Report
| Questions Correct | Questions Answered | Time Spent | Status | Attempt Date | |
|---|---|---|---|---|---|
| -- | -- | -- | -- | -- |
Previous Score Reports
| Questions Correct | Questions Answered | Time Spent | Status | Attempt Date | |
|---|---|---|---|---|---|
| -- | -- | -- | -- | -- |
The world's fastest mammal
Array
(
[passage] => WP_Post Object
(
[ID] => 556506
[post_author] => 12815
[post_date] => 2025-01-09 07:11:00
[post_date_gmt] => 2025-01-09 12:11:00
[post_content] => Practice Passage (Question 1-5)
*This passage is the property of Khan Academy and has been reformatted into an AAMC-style interface in their entirety by MedLife Mastery. MedLife Mastery does not endorse and is not an affiliate of Khan Academy.
The cheetah is the fastest mammal in the world, with a maximum accelerative ability of roughly 9 m/s². Scientists have attributed this remarkable ability to the cheetah’s unique physical composition. Evolutionary specialization led to the species’ small, lithe build, which makes the cat aerodynamic. The cheetah’s respiratory and circulatory system are abnormally large to allow for quicker oxygen uptake. Finally, its exceptionally long, muscular tail acts as a counter-torque mechanism to maintain the cheetah’s balance and center of mass during high-speed chases. See Figure 1.
Figure 1. While chasing prey, the cheetah’s tail acts as a rudder and counters the body’s movement during sharp turns.
Scientists interested in further studying the physical properties of cheetahs travel to the African savannah. There, they observe a cheetah that is hiding in the tall brush. A gazelle runs right past the hiding cheetah. Immediately after the gazelle passes the cheetah, the cheetah starts to pursue the unsuspecting gazelle.
The velocity vs. time graphs for the animals in this scenario are given below. At time t=0 seconds the cheetah emerges from the brush.
Figure 2. The velocity vs time graph of both the cheetah and the gazelle.
[post_title] => The world's fastest mammal
[post_excerpt] =>
[post_status] => publish
[comment_status] => closed
[ping_status] => closed
[post_password] =>
[post_name] => worlds-fastest-mammal
[to_ping] =>
[pinged] =>
[post_modified] => 2025-01-09 07:11:00
[post_modified_gmt] => 2025-01-09 12:11:00
[post_content_filtered] =>
[post_parent] => 0
[guid] => https://medlifemastery.com/?post_type=passage&p=556506
[menu_order] => 0
[post_type] => passage
[post_mime_type] =>
[comment_count] => 0
[filter] => raw
)
[questions] => Array
(
[0] => Array
(
[quiz_unique_key] => 578908434
[question] => How far have the gazelle and cheetah traveled after 1 second?
[value] => Array
(
[answer] => 1
[description] => Reason for the Correct Answer:
The area under the velocity vs. time graphs give the distance traveled by the animals.
The area under the gazelle’s velocity graph is a rectangle so it can be found by using the formula A=height x width. The area under the cheetah’s velocity graph is a triangle so it can be found by using the formula A= ½(height x base).
For the cheetah’s graph, the base of the triangle is 1sec and the height is 5m/s. For the gazelle’s graph, the width is 1sec and the height is 10m/s.
Plugging into the area formula you can find that for the gazelle, A = 10m/s x 1 sec = 10m, and for the cheetah, A = ½ x 5m/s x 1 sec = 2.5m.
)
[answers] => Array
(
[0] => Array
(
[each_answer] => A. gazelle 10m, cheetah 2.5m
)
[1] => Array
(
[each_answer] => B. gazelle 5m, cheetah 5m
)
[2] => Array
(
[each_answer] => C. gazelle 20m, cheetah 10m
)
[3] => Array
(
[each_answer] => D. gazelle 10m, cheetah 5m
)
)
)
[1] => Array
(
[quiz_unique_key] => 3873426850
[question] => What is the acceleration of the cheetah?
[value] => Array
(
[answer] => 2
[description] => Reason for the Correct Answer:
The definition of acceleration is a = Δv/Δt.
The slope of a velocity vs. time graph gives the acceleration.
Choose two points on the cheetah’s graph and solve for slope by using (v2-v1)/(t2-t1)
Plug in v₂=20m/s, t₂=4sec and v₁=0m/s, t₁=0sec into the formula for slope to get (20m/s)/(4sec) = 5m/s²
)
[answers] => Array
(
[0] => Array
(
[each_answer] => A. 2.5 m/s²
)
[1] => Array
(
[each_answer] => B. 5 m/s²
)
[2] => Array
(
[each_answer] => C. 20 m/s²
)
[3] => Array
(
[each_answer] => D. 0 m/s²
)
)
)
[2] => Array
(
[quiz_unique_key] => 83407773
[question] => What is the speed of the cheetah after 1.2 seconds?
[value] => Array
(
[answer] => 2
[description] => Reason for the Correct Answer:
The cheetah starts from rest so the initial velocity is zero.
The cheetah accelerates from rest, with 5.0m/s² for 4 seconds.
Use the formula for acceleration a = Δv/Δt.
Plug in vᵢ=0, t=1.2 seconds, and a=5.00m/s2 into the formula a = (vբ–vᵢ)/t and solve for v. Therefore, v=6 m/s
)
[answers] => Array
(
[0] => Array
(
[each_answer] => A. 5.5 m/s
)
[1] => Array
(
[each_answer] => B. 6.0 m/s
)
[2] => Array
(
[each_answer] => C. 6.5 m/s
)
[3] => Array
(
[each_answer] => D. 5.0 m/s
)
)
)
[3] => Array
(
[quiz_unique_key] => 2261298308
[question] => How far have the gazelle and cheetah traveled after 1 second?
[value] => Array
(
[answer] => 2
[description] => Reason for the Correct Answer:
The area under the velocity vs. time graphs give the distance traveled by the animals.
The area under the gazelle’s velocity graph is a rectangle so it can be found by using the formula A=height x width. The area under the cheetah’s velocity graph is a triangle so it can be found by using the formula A= ½(height x base).
For the cheetah’s graph, the base of the triangle is 1sec and the height is 5m/s. For the gazelle’s graph, the width is 1sec and the height is 10m/s.
Plugging into the area formula you can find that for the gazelle, A = 10m/s x 1 sec = 10m, and for the cheetah, A = ½ x 5m/s x 1 sec = 2.5m.
)
[answers] => Array
(
[0] => Array
(
[each_answer] => A. gazelle 10m, cheetah 5m
)
[1] => Array
(
[each_answer] => B. gazelle 10m, cheetah 2.5m
)
[2] => Array
(
[each_answer] => C. gazelle 5m, cheetah 5m
)
[3] => Array
(
[each_answer] => D. gazelle 20m, cheetah 10m
)
)
)
[4] => Array
(
[quiz_unique_key] => 2261298308
[question] => At what time after emerging from the brush, does the cheetah catch the gazelle?
[value] => Array
(
[answer] => 4
[description] => Reason for the Correct Answer:
The area under the velocity vs. time graphs give the distance traveled by the animals.
The cheetah will catch the gazelle when both animals have simultaneously traveled the same distance.
The area under the gazelle’s velocity graph is a rectangle so it can be found by using A = height x width. The area under the cheetah’s velocity graph is a triangle so it can be found by using the formula A = ½ base x height.
The areas under the curves are equal at 4 seconds since the gazelle traveled a distance 10m/s x 4 seconds = 40m, and the cheetah traveled ½ x 20m/s x 4 seconds = 40m.
)
[answers] => Array
(
[0] => Array
(
[each_answer] => A. After 2 seconds
)
[1] => Array
(
[each_answer] => B. After 3 seconds
)
[2] => Array
(
[each_answer] => C. After 2.5 seconds
)
[3] => Array
(
[each_answer] => D. After 4 seconds
)
)
)
)
[total_question] => 5
[correct_answers] => Array
(
[556506|1] => A
[556506|2] => B
[556506|3] => B
[556506|4] => B
[556506|5] => D
)
[hide_display_feedback_settings] =>
[hide_solutions] =>
)
Scientists interested in further studying the physical properties of cheetahs travel to the African savannah. There, they observe a cheetah that is hiding in the tall brush. A gazelle runs right past the hiding cheetah. Immediately after the gazelle passes the cheetah, the cheetah starts to pursue the unsuspecting gazelle.
The velocity vs. time graphs for the animals in this scenario are given below. At time t=0 seconds the cheetah emerges from the brush.
Figure 2. The velocity vs time graph of both the cheetah and the gazelle.
[post_title] => The world's fastest mammal
[post_excerpt] =>
[post_status] => publish
[comment_status] => closed
[ping_status] => closed
[post_password] =>
[post_name] => worlds-fastest-mammal
[to_ping] =>
[pinged] =>
[post_modified] => 2025-01-09 07:11:00
[post_modified_gmt] => 2025-01-09 12:11:00
[post_content_filtered] =>
[post_parent] => 0
[guid] => https://medlifemastery.com/?post_type=passage&p=556506
[menu_order] => 0
[post_type] => passage
[post_mime_type] =>
[comment_count] => 0
[filter] => raw
)
[questions] => Array
(
[0] => Array
(
[quiz_unique_key] => 578908434
[question] =>