Relative motion -cheetah and gazelle

In summary, the gazelle will run an additional 55.9 meters after the 70 m mark, so the cheetah will catch it after 4.53 seconds.
  • #1
Kristin_Z
9
0

Homework Statement


A cheetah can run at approximately 100km/hr and a gazelle at 80km/hr. If both animals are running at full speed, with the gazelle 70m ahead, how long before the cheetah catches its prey?

Homework Equations


s=vt (no acceleration)
v = km/hr / 3.6 = m/s

The Attempt at a Solution


I understand that this is relative motion. I've calculated that it takes the cheetah 2.52 s to run 70m and that during that 2.52 sec the gazelle would run an additional 55.9 m so that the total distance that the cheetah has to run is 125.9 meters. I've calculated that the time it takes for the cheetah to run this distance at constant speed is 4.53 s. I've redone this question about 10 times and can't figure out what I'm doing wrong. Can anyone please shed some light on what is probably a ridiculously easy question. Thank you.
 
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  • #2
Kristin_Z said:

Homework Statement


A cheetah can run at approximately 100km/hr and a gazelle at 80km/hr. If both animals are running at full speed, with the gazelle 70m ahead, how long before the cheetah catches its prey?

Homework Equations


s=vt (no acceleration)
v = km/hr / 3.6 = m/s

The Attempt at a Solution


I understand that this is relative motion. I've calculated that it takes the cheetah 2.52 s to run 70m and that during that 2.52 sec the gazelle would run an additional 55.9 m so that the total distance that the cheetah has to run is 125.9 meters. I've calculated that the time it takes for the cheetah to run this distance at constant speed is 4.53 s. I've redone this question about 10 times and can't figure out what I'm doing wrong. Can anyone please shed some light on what is probably a ridiculously easy question. Thank you.

Make things simpler on yourself. Put yourself inside the head of the cheetah.

The cheetah sees dinner just 70 m away, and coming closer at the rate of 20 km/h.

Looked at another way, a student is waiting for a Pop Tart being delivered on a conveyor belt going at 20 km/h. The cafeteria worker is putting it on the conveyor from 70 m away. How long?

So how long does it take for that meal going at 20 km/h to travel 70m?
 
  • #3
I've been looking at relative motion equations in 2d and having no problem but when I saw this one my brain was certain that somehow it had to be super complicated. Its not though. Thanks, is all makes sense now.
 

FAQ: Relative motion -cheetah and gazelle

What is relative motion?

Relative motion is the movement of an object in relation to another object. It is measured as the change in position of the object over time.

How does relative motion apply to cheetahs and gazelles?

Cheetahs and gazelles are both animals that exhibit relative motion as they move through their environment. The cheetah and gazelle are constantly moving in relation to each other as they chase and evade each other in a predator-prey relationship.

What factors affect relative motion between cheetahs and gazelles?

The relative motion between cheetahs and gazelles can be affected by various factors such as the speed and agility of each animal, the terrain they are running on, and any obstacles in their path. Wind resistance and friction can also play a role in the relative motion of these animals.

How does relative motion impact the hunting and evasion strategies of cheetahs and gazelles?

Relative motion plays a crucial role in the hunting and evasion strategies of cheetahs and gazelles. The cheetah's ability to run at high speeds allows it to close the gap between itself and the gazelle, while the gazelle's agility and quick change of direction allows it to evade the cheetah's pursuit.

Can relative motion be applied to other animals or objects?

Yes, relative motion is a concept that can be applied to any moving object in relation to another object. It is a fundamental concept in physics and is used to understand the movement of objects in our world.

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