Common errors and little tips and tricks (1 Viewer)

[Zeref]

So today I decided to do some calculations for physics and I noticed that I sometimes forget a little step or "tricks".

One example is:

Calculate the change in GPE in moving a 10 kg object from an initial position 1000 km above the surface of the Earth to a final position at a distance from the Earth equivalent to the mean orbital radius of the Moon (r = 3.84 × 10^8 m). Assume the Moon is on the opposite side of its orbit at the time and you can ignore its gravitational effect.

I was stuck on this question for some time and Fizzy_Cyst pointed out to me that I forgot to add the Earth's radius onto the 1000 km altitude as I completely forgot about the "distance from centre of object"

To prevent myself from making these mistakes again, I was thinking of compiling this into a document, make sure I remember it and then do similar questions afterward. Is there anyone here that would be interested in making this together? An example of a "trick" could be for projectile motion, the maximum possible height occurs at a launch angle of 90 degrees and the maximum horizontal range occurs at a launch angle of 45 degrees.

Comment or PM if you're interested

Also if you're reading Anomalousdecay, thanks for answering my endless amount of questions

 

[Zeref]

bumpppp

 

[timeflies]

good idea! do it by urself and ull benefit much more and realise your strengths and weaknesses and work with that to consolidate your knowledge and perfect your question answering techniques ;D

Sent from my Nexus 5 using Tapatalk

 

[Zeref]

good idea! do it by urself and ull benefit much more and realise your strengths and weaknesses and work with that to consolidate your knowledge and perfect your question answering techniques ;D

Sent from my Nexus 5 using Tapatalk

yup, I just want to compare with people to make sure I'm not missing out on anything

 

[anomalousdecay]

Just to test your understanding on Space so far, I will give you guys a common misconception to think about:

A bullet is fired from a gun, parallel to the ground, on a completely level ground, so that wherever the bullet lands, it is at the same height as the feet of the shooter.

The bullet leaves the barrel at the same time that the shell casing is sprung out and dropped from the gun.

Which hits the ground first? The bullet or the shell casing?

 

[gwilymprice]

Just to test your understanding on Space so far, I will give you guys a common misconception to think about:

A bullet is fired from a gun, parallel to the ground, on a completely level ground, so that wherever the bullet lands, it is at the same height as the feet of the shooter.

The bullet leaves the barrel at the same time that the shell casing is sprung out and dropped from the gun.

Which hits the ground first? The bullet or the shell casing?

So what h

Our teacher asked a similar question one time and the lesson ended up being some kid arguing the answer for ages, basically claiming Galileo to be wrong haha. Then again the same kid claimed time dilation to be wrong haha

 

[Zeref]

Just to test your understanding on Space so far, I will give you guys a common misconception to think about:

A bullet is fired from a gun, parallel to the ground, on a completely level ground, so that wherever the bullet lands, it is at the same height as the feet of the shooter.

The bullet leaves the barrel at the same time that the shell casing is sprung out and dropped from the gun.

Which hits the ground first? The bullet or the shell casing?

So what h

I believe they land on the ground at the same time. I watched an experiment similar to this except it was 2 balls at the same height that was horizontally "pushed out" at different velocities. I think the answer is that the horizontal and vertical components are independent of each other. (because Galileo said so)

 

[anomalousdecay]

Our teacher asked a similar question one time and the lesson ended up being some kid arguing the answer for ages, basically claiming Galileo to be wrong haha. Then again the same kid claimed time dilation to be wrong haha

lol

 

[anomalousdecay]

I believe they land on the ground at the same time. I watched an experiment similar to this except it was 2 balls at the same height that was horizontally "pushed out" at different velocities. I think the answer is that the horizontal and vertical components are independent of each other. (because Galileo said so)

Correct. It is not simply because Galileo said so, but rather as an effect of gravity.

Remember two objects will accelerate towards each other at equal rates as a result of gravity.

Assuming that the mass difference is negligible (Anything less than a million tonnes is negligible probably), they will hit the ground at the same time. The vertical components will be the same.