Physics Questions

MCAT_Retaker
Posts: 90
Joined: Thu Feb 01, 2018 3:58 am

Physics Questions

Post by MCAT_Retaker » Fri Mar 02, 2018 3:37 pm

Can you explain question 2 and 3 from chapter 2. i can follow the explanation for 2 all the way until it says 10=T(.25). I dont know where that is coming from. The distance in a torque is just the distance away the mass is, right? For 2, the explanation doesnt give an angle for m2, but thats just sin 90 as well right?

Thank you,
NS_Tutor_Andrew
Site Admin
Posts: 520
Joined: Mon May 23, 2016 1:47 pm

Re: Physics Questions

Post by NS_Tutor_Andrew » Fri Mar 02, 2018 5:04 pm

Hi MCAT_Retaker,

Yes -- I'd be happy to! This is definitely a tough passage and one that many students have questions about, so you're in good company. I've typed out an explanation using more sophisticated/clearer equation typesetting than is possible in plain text in the forum and I've attached the screenshot. Hopefully this should clarify matters. The explanation is specifically for Q2, but once you thoroughly work out what's going on in Q2, Q3 is a straightforward extra step to calculate the x-component.

Hope this helps and let me know if you have any follow-up questions!
Attachments
Screen Shot 2018-03-02 at 2.01.57 PM.png
(165.61 KiB) Not downloaded yet
Andrew D.
Content Manager, Next Step Test Prep.
MCAT_Retaker
Posts: 90
Joined: Thu Feb 01, 2018 3:58 am

Re: Physics Questions

Post by MCAT_Retaker » Sat Mar 10, 2018 9:03 pm

im honeslty still confused with this passage. for 3. they are using Fx=46 N * cos 60 degrees

isnt the 46 N the y component of M1, then to solve for the x component, you would need a tangent?

When they mean the tension, what do they mean the x componet or the hypotenuse?

if you can possible show 2-4 with pictures, that might help.
MCAT_Retaker
Posts: 90
Joined: Thu Feb 01, 2018 3:58 am

Re: Physics Questions

Post by MCAT_Retaker » Sun Mar 11, 2018 1:43 pm

[quote="MCAT_Retaker"]im honeslty still confused with this passage. for 3. they are using Fx=46 N * cos 60 degrees

isnt the 46 N the y component of M1, then to solve for the x component, you would need a tangent?

When they mean the tension, what do they mean the x componet or the hypotenuse?
NS_Tutor_Andrew
Site Admin
Posts: 520
Joined: Mon May 23, 2016 1:47 pm

Re: Physics Questions

Post by NS_Tutor_Andrew » Sun Mar 11, 2018 10:35 pm

Hi MCAT_Retaker --

Just as a quick reply for now (I'll follow up with a picture) --

46N is the magnitude of the force due to M1, i.e. the hypotenuse. So no tangent is necessary. That force is also the tension.

More later :)
Andrew D.
Content Manager, Next Step Test Prep.
NS_Tutor_Andrew
Site Admin
Posts: 520
Joined: Mon May 23, 2016 1:47 pm

Re: Physics Questions

Post by NS_Tutor_Andrew » Mon Mar 12, 2018 6:29 pm

Hi MCAT_Retaker,

I'm attaching a diagram of the setup with color-coded forces/torques. Hopefully this will help clarify things!
Attachments
Screen Shot 2018-03-12 at 3.27.54 PM.png
(214.52 KiB) Not downloaded yet
Andrew D.
Content Manager, Next Step Test Prep.
MCAT_Retaker
Posts: 90
Joined: Thu Feb 01, 2018 3:58 am

Re: Physics Questions

Post by MCAT_Retaker » Thu Mar 15, 2018 10:29 pm

thank you. i was watching this video, and i believe he says something wrong. 1 Calorie is equal to 1 kcal, not 1000 kcal.
Maybe I heard wrong but he says it between 2 and 3 min. Video #5 on the heat and phase change concept video.
MCAT_Retaker
Posts: 90
Joined: Thu Feb 01, 2018 3:58 am

Re: Physics Questions

Post by MCAT_Retaker » Fri Mar 16, 2018 1:42 am

can you explain this?
Attachments
Screen Shot 2018-03-15 at 10.41.53 PM.png
(95.89 KiB) Not downloaded yet
NS_Tutor_Andrew
Site Admin
Posts: 520
Joined: Mon May 23, 2016 1:47 pm

Re: Physics Questions

Post by NS_Tutor_Andrew » Fri Mar 16, 2018 2:22 pm

Hi MCAT_Retaker,

Re: the Calorie/kilocalorie thing, yes, you heard right & we have made a note of it to fix.

Re: the mechanical energy question, I believe that all 3 answer choices should be selected, because the PE changes as the egg falls and its KE goes to zero as it hits the ground. (Arguably, the kinetic energy would be transferred to the various shards of the broken egg at least at first, but then they too fall to the ground). We'll fix that ASAP.

Thanks for pointing these out!!
Andrew D.
Content Manager, Next Step Test Prep.
MCAT_Retaker
Posts: 90
Joined: Thu Feb 01, 2018 3:58 am

Re: Physics Questions

Post by MCAT_Retaker » Sat Mar 17, 2018 12:37 am

No Problem.

I'm looking at the answer explanation for Chapter 3: Energy Chapter. Page 75. For question 7, how are they getting the mass of skater 2. If that refers to Test 2, I get it, but the question doesn't say anything about Test 2. So the 30 kg??

Can you also furthr explain question 2 from chapter 4 Physics Passage. Page 93.
Locked