Physics Assessment #71????

[MedGrl@2022]

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I did not even understand what this question was talking about... I am sure if I understood the question I could have solved it easily...

There are two cars in this passage both initially 100m apart. Car A travels 30m/s, Car B travels 20 m/s on a highway in the same direction.

"How long before test car A overtakes car B?"

A) 2s
B) 3.33s
C) 5s
D) 10s

The answer was D. AAMC says that "The passage tells us during each second Car A travels 30 m and Car B travels 20 m. To make up 100 m the two cars must travel 10 seconds. This is answer D.

What does the question mean by "overtakes"? I don't understand the question or answer.

Thank you for your help! 🙂

 

[Postictal Raiden]

I did not even understand what this question was talking about... I am sure if I understood the question I could have solved it easily...

There are two cars in this passage both initially 100m apart. Car A travels 30m/s, Car B travels 20 m/s on a highway in the same direction.

"How long before test car A overtakes car B?"

A) 2s
B) 3.33s
C) 5s
D) 10s

The answer was D. AAMC says that "The passage tells us during each second Car A travels 30 m and Car B travels 20 m. To make up 100 m the two cars must travel 10 seconds. This is answer D.

What does the question mean by "overtakes"? I don't understand the question or answer.

Thank you for your help! 🙂

They mean "how will it take Car A to pass by Car B?". Car B is driving 100m ahead of Car A, but car A is traveling at a greater speed, so, eventually, Car A will "overtake" Car B.

An easy way to approach this problem is to assume that car B is stationary, 100m away from car A, which is approaching it at a speed of 10m/s. Now, it's a simple math problem to find how long it will take car B traveling at speed of 10m/s to travel 100m.

 

[EmergentCough]

The question just means at what point will the second car begin to pass the first, or, in physics equations forms, when will Xa=Xb. Solve like this:

Xf=Xi + Vt

The initial point of car B is 100 meters in front of A, or Xb=100 and Xa=0.

Xfa= 30 m/s x time
Xfb= 100+ 20m/s X time

We want when the Xf are the same, so set them equal to each other.

30(t)=100+20(t)

Solve for t

 

[MedGrl@2022]

The question just means at what point will the second car begin to pass the first, or, in physics equations forms, when will Xa=Xb. Solve like this:

Xf=Xi + Vt

The initial point of car B is 100 meters in front of A, or Xb=100 and Xa=0.

Xfa= 30 m/s x time
Xfb= 100+ 20m/s X time

We want when the Xf are the same, so set them equal to each other.

30(t)=100+20(t)

Solve for t

Awesome! Sometimes I just make questions a lot harder than they actually are! lol... such is life... Thank you for all your help! 🙂