We are standing at a distance d=15 m away from a house. The house wall is h=6 m high and the roof has an inclination angle β=30 ∘. We throw a stone with initial speed v0=20 m/s at an angle α= 35 ∘. The gravitational acceleration is g=10 m/s2. (See figure)
(a) At what horizontal distance from the house wall is the stone going to hit the roof - s in the figure-? (in meters)
b) What time does it take the stone to reach the roof? (in seconds)
physics (it's rather urgent help is appreciated -
bobpursley,
height of roof: 6+ slope*(distance-15)
slope=sin30 notice distance is the horizontal distance from the wall. distance=vo*cos35*timeinair you know vo, given.
so using that height funcion,
hf=heightof roof=voSin35*time-4.9t^2
or
[6+ sun30*(distance-15)]*=
6+ sun30*(20*cos35*t -15)=20cos30*t-4.9t^2
solve for time in air, t. That is when it hits the roof.
Now, putting that into the horizontal distance equation: 20*cos35*t
physics (it's rather urgent help is appreciated -
ss01,
its wrong....
physics (it's rather urgent help is appreciated -
kyle,
ss01 how do you solve this then
physics (it's rather urgent help is appreciated -
Phy,
Even I wanted to know how to solve this problem.
Can any one tell me how to solve the first problem of the exam?
I got the answers of all problems except these 2.
physics (it's rather urgent help is appreciated -
ss01,
i got it wrong followed your ways
physics (it's rather urgent help is appreciated -
ss01,
@phy what other questions did you got? i got 1st one
physics (it's rather urgent help is appreciated -
kyle,
i got all except this one
physics (it's rather urgent help is appreciated -
Phy,
kyle and ss01 can you please tell me how to solve the 1st problem?
physics (it's rather urgent help is appreciated -
kyle,
which part?
physics (it's rather urgent help is appreciated -
ss01,
keep on differentiating and put the time value u vl get it
physics (it's rather urgent help is appreciated -
ss01,
@kyle could you plz tell me how to do 2 & 3
physics (it's rather urgent help is appreciated -
kyle,
@ss01 if you check homework 2 the 2nd last question it shows you how to do question 2.
for quetion 3 Ac must be 10m/s
so you get 10=v^2/r and from there you can solve since i don't know what value of r you got
physics (it's rather urgent help is appreciated -
ss01,
@ kyle what is the option for 3 question
my radius is 7m and mass is 5kg
physics (it's rather urgent help is appreciated -
Anonymous,
plz tell me how to do 5 & 6
physics (it's rather urgent help is appreciated -
ss01,
@kyle what is for south pole
physics (it's rather urgent help is appreciated -
Anonymous,
qustion 3
v=8.366
physics (it's rather urgent help is appreciated -
Anonymous,
south pole is 0
physics (it's rather urgent help is appreciated -
Anonymous,
ac=v^2/r
physics (it's rather urgent help is appreciated -
ss01,
@anonymous plz specify
physics (it's rather urgent help is appreciated -
Anonymous,
v=sqrt(r*g)
physics (it's rather urgent help is appreciated -
ss01,
kyle ...got the 2
physics (it's rather urgent help is appreciated -
ss01,
@anonymous what is the 3rd option for question 3
physics (it's rather urgent help is appreciated -
kyle,
@Anonymous how do you solve for the 7th question
physics (it's rather urgent help is appreciated -
ss01,
@kyle did you all the options for 6th one?
i got 1st 2 correct rest all wrong
physics (it's rather urgent help is appreciated -
Phy,
I didn't get you, can you explain it properly how to do the 1st problem
physics (it's rather urgent help is appreciated -
ss01,
for acceleration double differentiate the equation. you get only x and y vector left with some constant but no z vector
physics (it's rather urgent help is appreciated -
ss01,
i didn't got the speed
physics (it's rather urgent help is appreciated -
Phy,
Well, I don't know how to differentiate, can you explain it to me.
physics (it's rather urgent help is appreciated -
ss01,
you could search on youtube there are lot of good videos on it. there are various rules too be followed.
physics (it's rather urgent help is appreciated -
Phy,
Can you tell me how to calculate distance of the particle to the origin at time, speed of the particle and the smaller angle? I got the acceleration. Thanks
physics (it's rather urgent help is appreciated -
kyle(PLS HELP ),
distance is the magnitude of the position vectors
speed is the magnitude of the velocity vector and
for the angle its the z vector for velocity divided by the magnitude of the velocity
physics (it's rather urgent help is appreciated -
Phy,
Thanks. Did you get Stone On Roof Find Distance problem?
physics (it's rather urgent help is appreciated -
ss01,
@kyle did you got angle 0?
337.64 for dis?
physics (it's rather urgent help is appreciated -
kyle(PLS HELP ),
no, i think bobpursely was wrong, trying to get a second opinion
physics (it's rather urgent help is appreciated -
ss01,
@KYLE plz reply
physics (it's rather urgent help is appreciated -
ajay,
anyone for stone off a cliff question help?
physics (it's rather urgent help is appreciated -
Anonymous,
@ss01 for what question
physics (it's rather urgent help is appreciated -
ss01,
i got all except for stone on roof, find distance
physics (it's rather urgent help is appreciated -
ss01,
anyone any luck?
physics (it's rather urgent help is appreciated -
anon,
@ss01 did you manage to find the time?
physics (it's rather urgent help is appreciated -
ss01,
@anon for which question?
physics (it's rather urgent help is appreciated -
anon,
@ss01 for the inclined wall stone throw
physics (it's rather urgent help is appreciated -
ss01,
i didn' t got that, the 2nd last question right?
physics (it's rather urgent help is appreciated -
anon,
yeah
physics (it's rather urgent help is appreciated -
ss01,
did you got the hw3 question5 & 7
physics (it's rather urgent help is appreciated -
anon,
no
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