TBR Physics Chapter 1 question

[Perseverance7779311]

---

Members don't see this ad.

Hey guys, in TBR Physics Chapter 1, passage 1, question 3, it says...."Next, Galileo compares the range (i.e., horizontal distances traveled by the tossed stones) on each planet. He found that the stone in Trial D traveled:

A. 3 times as far as in Trial B
B. sqrt 2 times as far as in Trial B
C. 1/sqrt 2 as far as in Trial B
D. the same distance as in trial B

Background Info:
Galileo designs an experiment to study the effect of throwing a stone horizontally from the top of his 20m rocket. He tosses stone B from the top of the rocket while on earth and he tosses stone D from the top of the rocket while on Halfnia.

Trial g[m/s2] Vo [m/s]
Stone B 9.8 10.0
Stone D 4.9 5.0

 

[DrknoSDN]

C?

Solve for time in air for stone B and D. (2 and 2.82 sec)
Realize that horizontal velocity of D is half stone B.

Distance of Stone D is 2.82 sec * (1/2 B velocity) = 1.41 relative distance
Distance of B is 2 sec * (B velocity) = 2 relative distance

Stone D distance is shorter, and the ratio is 1/(root2) = 0.707

 

[orangetea]

I think an even more easier way to do is 5t^2=10t^2
and solve for t which gives you 1/sqrt(2)t(halfnia)=t earth.

🙂

 

[Perseverance7779311]

@DrknoSDN , thank you!
@orangetea, thank you!

 

[sillyjoe]

Hey guys, in TBR Physics Chapter 1, passage 1, question 3, it says...."Next, Galileo compares the range (i.e., horizontal distances traveled by the tossed stones) on each planet. He found that the stone in Trial D traveled:

A. 3 times as far as in Trial B
B. sqrt 2 times as far as in Trial B
C. 1/sqrt 2 as far as in Trial B
D. the same distance as in trial B

Background Info:
Galileo designs an experiment to study the effect of throwing a stone horizontally from the top of his 20m rocket. He tosses stone B from the top of the rocket while on earth and he tosses stone D from the top of the rocket while on Halfnia.

Trial g[m/s2] Vo [m/s]
Stone B 9.8 10.0
Stone D 4.9 5.0

I just went ahead and looked up this question. In my book this is question 6 and the answer is B.

The answer for question 3 is 1/sqrt(2) because it is looking for flight time.

Can you please clarify which question you are referring to?

 

[DrknoSDN]

I just went ahead and looked up this question. In my book this is question 6 and the answer is B.

The answer for question 3 is 1/sqrt(2) because it is looking for flight time.

Can you please clarify which question you are referring to?

Probably because the table may be different for OP.. Or the problem was copied down incorrectly.
Actual Passage information for 2012 ed. shows:

Compared to OP where StoneB has Vo of 10 m/s... Changing Vo will surely change relative distance.

 

[sillyjoe]

Probably because the table may be different for OP.. Or the problem was copied down incorrectly.
Actual Passage information for 2012 ed. shows:
View attachment 183011

Compared to OP where StoneB has Vo of 10 m/s... Changing Vo will surely change relative distance.

It's not the table that is different, I think he is confusing two questions.

 

[DrknoSDN]

It's not the table that is different, I think he is confusing two questions.

Maybe, but the 2012 edition does not have the same information that is provided in the original post.

Trial g[m/s2] Vo [m/s]
Stone B 9.8 10.0
Stone D 4.9 5.0

This may have changed between versions. Could also be wrong question.
I would assume question number changed and he wanted to know about the question stated, as it was quoted verbatim.