Question

What are the assumptions for free-fall problems?

Answer 1

do u have any idea about assumptions?

Answer 2

I think so..

Answer 3

I mean I know that when an object is dropped from a height you assume its initial velocity as 0.

Answer 4

so tell...what do we assume in free-fall problems?

Answer 5

that's all I know for now.

Answer 6

it's an assumption?...u just release the object then it implies that speed of object is zero...

Answer 7

suppose u throw the object vertically upward with a velocity....

Answer 8

does it reach a peak and go down? or it just goes then down..

Answer 9

it'll reach a peak and at the peak speed of object will be zero and then it'll starts to fall down

Answer 10

these are not assumptions of free fall...

Answer 11

1st tell me..what is free fall?

Answer 12

what are they called then?

Answer 13

http://www.frigginphysics.com/2011/01/the-physics-of-free-falling-bodies/

in this site it says it is....

Answer 14

free fall: experiences a downward acceleration of 9.8m/s/s

Answer 15

yes...:)

Answer 16

have you seen the site?

Answer 17

suppose when i throw an object upward then what will be the acceleration?

Answer 18

here it's written...What Your Physics Textbook Assumes You Know..
it doesnt mean that these are the assumptions of free fall

Answer 19

yes...when we solve problems of free fall or we use kinematic equations...we make some assumptions..

Answer 20

like air resistance is zero...acceleration due to gravity is constant throughout the motion

Answer 21

the a upward would be -9.8m/s/s ?

Answer 22

now tell me...what do u mean by acceleration due to gravity?

Answer 23

also why is it -9.8m/s/s downwards? and my teacher says that it's also -9/8m/s/s upwards?

Answer 24

I just don't get that....

Answer 25

just wait...there r some misconceptions..where r u from?

Answer 26

Philippines.... sadly.

Answer 27

Whether the object is falling downward or rising upward towards its peak, if it is under the sole influence of gravity, then its acceleration value is 9.8 m/s/s.

Answer 28

ok

Answer 29

contradicts with this statement An object in free fall experiences an acceleration of -9.8 m/s/s. (The - sign indicates a downward acceleration.) Whether explicitly stated or not, the value of the acceleration in the kinematic equations is -9.8 m/s/s for any freely falling object.

Answer 30

it says in the first statment: 9.8m/s/s but in the second it says -9/8m/s/s....

Answer 31

i don't get it

Answer 32

wow....u have struggled a lot...great!

Answer 33

tbh, I can't do it anymore, super failing in physics...

Answer 34

let's start...as i asked...what's acceleration due to gravity?

Answer 35

Earth pulls every object towards itself with acceleration of 9.8 m/s/s

Answer 36

right?

Answer 37

yes. okay.

Answer 38

acceleration due to gravity is a vector quantity?

Answer 39

yes.

Answer 40

so it should have magnitude along with direction?

Answer 41

yes. .

Answer 42

so magnitude of acceleration due to gravity= 9.8m/s/s

Answer 43

okay.

Answer 44

there is no + or - with the magnitude of any vector quantity

Answer 45

why is that? isn't it that if the direction is eastward its + and the direction westward is - ?

Answer 46

now we take a problem

Answer 47

just wait...we will discuss them later

Answer 48

now we concentrate on the above problem

Answer 49

I cannot comprehend your diagram..

Answer 50

I'll explain...

Answer 51

it's fine?

Answer 52

okay. :)

Answer 53

what's u?

Answer 54

thank you demitris. :D

Answer 55

now we have to calculate after what time it'll reach the peak?

Answer 56

and for doing any measurement, we need frame of reference.

Answer 57

wait... a min

Answer 58

when our teacher discussed kinematics and free fall he did not talk about frame reference, he will talk about it sometime this month but we are now starting a new term.....

Answer 59

just wait...i'll come to your questions..

Answer 60

let me tell what do I mean my some reference for doing the measurement

Answer 61

alright :D

Answer 62

alright