• Congratulations to the Class of 2024 on your results!
    Let us know how you went here
    Got a question about your uni preferences? Ask us here

asap need help with this projectile q (1 Viewer)

medaspirant

Member
Joined
Oct 18, 2021
Messages
51
Gender
Male
HSC
2022
1641352737179.png
im getting answer as 1.16 but with some eq which i dont know a lot bout. like i researched and found this hang time equation:
t = 2vsintheta / g
and like others have also utilised this formula in their explanation but idk if it is correct. also if someone could tell me how this is derived and whether its like assumed / common knowledge this formula.
i saw this method in this website:
www. gauthmath.com/solution/1-A-projectile-is-launched-from-point-O-at-an-angle-of-22-circ-with-an-initial-v-1701876453272582
remove the space after www. for link to work

another method i saw is
brainly. in/question/12137403
remove space after brainly. for link to work

but i dont rlly understand so like if someone could guide me in how to approach this q it would be appreciated.
 

Lith_30

o_o
Joined
Jun 27, 2021
Messages
158
Location
somewhere
Gender
Male
HSC
2022
Uni Grad
2025
You can solve this question like finding the point of intersection between two graphs.

The relationship between the horizontal run and vertical rise of the incline plane is

For the projectile we know that and . Then to find the horizontal displacement of the projectile we use.

So now we want to find the value of time for which the rise and run of the incline plane is the same as the vertical and horizontal displacement of the projectile. To do this we solve both the equations for the incline plane and the horizontal displacement of the projectile simultaneously.



We know that so...



We're only interested in the second answer, so lets sub in the values for that answer.

 

ExtremelyBoredUser

Bored Uni Student
Joined
Jan 11, 2021
Messages
2,479
Location
m
Gender
Male
HSC
2022
im getting answer as 1.16 but with some eq which i dont know a lot bout. like i researched and found this hang time equation:
t = 2vsintheta / g
and like others have also utilised this formula in their explanation but idk if it is correct. also if someone could tell me how this is derived and whether its like assumed / common knowledge this formula.
Sure.


At the peak, the vertical velocity will be 0.


Rearranging variables.

Now the motion is clearly symmetrical, and therefore you can deduce that the time taken to reach the peak is equal to the time taken to reach the landing point, as it clearly lands on the same angle of elevation as it is launched from.

Hence;


another form of writing u_y

Substituting this


And hence the time equation.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top