How Do You Calculate Displacement and Time of Flight When Sliding Off a Roof?

  • Thread starter Thread starter Inertialforce
  • Start date Start date
  • Tags Tags
    Projectiles
AI Thread Summary
To calculate the displacement and time of flight when sliding off a roof inclined at 25 degrees, the initial velocity is 5.36 m/s and the height is 9.25 m. The horizontal component of the velocity is found to be approximately 4.86 m/s. Using the equations of motion, the final vertical velocity is calculated to be 14.5 m/s, leading to a time of flight of about 0.933 seconds. The horizontal displacement during this time is determined to be approximately 4.53 meters. The calculations and methods used for both parts of the problem appear to be correct.
Inertialforce
Messages
67
Reaction score
2

Homework Statement


On a snowy winter day, you decide to slide off the roof of your home. The roof has an angle of inclination equal to 25.0 degrees. Given that you leave the edge of the roof with a velocity of 5.36m/s and the edge of the roof is 9.25m above the ground level. Determine:

a)Your total horizontal displacement
b)Your total time of flight


Homework Equations


Vx = dx/t
Vfy = Viy -gt
Vfy(squared) = Viy(squared) - 2gdy

The Attempt at a Solution


First I wrote down what I was given and what I could easily derive:

theta = 25(degrees)
h = dy = 9.25m
Viy = 5.36m/s
g = 9.80m/s

Vx = (cos(25))(5.36) = 4.8578 m/s

Then I went:
Vfy(squared) = Viy(squared) - 2gdy

I then put in my values and the answer I got for Vfy is:

Vfy = 14.5m/s

Then I used the equation:

Vfy = Viy -gt

and I isolated the t and plugged in all my variables and the answer I got for t is:

t = 0.933s

Then I used the equation:

Vx = dx/t
(Vx)(t) = dx

I then plugged in the two values (Vx and t) which I found out from my previous calculations and I got an answer for dx:

dx = 4.53m

b) For part "b" I used the equation:

Vfy = Viy - 2gt

then I isolated the t value and put in my values (some of which I found out in part a) to solve for t and I got:

t= 0.933s

I know this may seem like a really long question but could someone double check the answers that I got or tell me if the method I used in both question is correct or not? I would greatly appreciate it.
 
Physics news on Phys.org


you leave the edge of the roof with a velocity of 5.36m/s in the direction of the inclination of the roof. There fore Viy = sin(25)(5.36)
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top