help on Q4 + Q15 in phys specimen paper (1 Viewer)

[Sirius Black]

In the solution provided by Success One Book
Q4-A
Why isn't the hammer experiencing centripedal acceleration towards the center of the Earth when its dropped from geosychronous orbit as in (B)?

Q15-D
Doesn't radio wave always travel at C regardless of medium? if so, if the frequency is the same,then wavelength=c/f should be the same as well right?
then the choice would be B

Could any1 help plz? thanx

 

[jake2.0]

this is from the 2001 specimen paper right, the MC section??
question 4 is about some graphs

 

[exa_boi87]

Correct me if im wrong, but for centripetal force, or any orbit whatsoever to occur, an object must enter the earths orbit with a velocity, hence why satellites are equipped with boosters, using Newtons concept of projectile motion that an object launched with enough horizontal velocity can enter the earths orbit, we see that a hammer simply dropped does not posess a horizontal velocity toward the earths orbital motion.
Especially at that height, 35,800 wouldnt posess a large gravitational pull (in comparison to low orbit) and at that radius, the mass of a hammer divided by 35800X10^3 would be quite insignificant.

Just taking a stab though, we'll see what the others come up with today

15. Yes, radio waves are an electromagnetic wave and as such travel at "c", however their frequency changes! ... think about your radio ... 96.9, 104.1 ... all changes in frequency to recieve a station. As that equation correctly identifies, a change in frequency relfects a change in wavelength.

 

[Haku]

but i am pretty sure that the speed could be altered through mediums...

and for the hammer question. it does not have a horizontal velocity. For an object to have centripetal force, it must have a force to the center of motion (earth) and a equal force forward horizontally (the velocity)

 

[Abtari]

specimen paper? where can one get that?

 

[helper]

The velocity is not a force. In circular motion there is a net force towards the centre. The inertia to keep heading off as a tangent is not a force.

 

[spank_meh]

specimen paper? where can one get that?

lol dude first you get success one then u find a specimen paper in it... i doubt that you have any chances in getting the book but yer

 

[jake2.0]

you can download the specimen paper from the BOS website, its on the page where the physics syllabus is

 

[spank_meh]

you can download the specimen paper from the BOS website, its on the page where the physics syllabus is

pardon me my english i just thought that specimen paper was err something different haha sorry

damm im confused i cant find the hammer question hmm.... :s