Answer:
t = 1.31 s
Explanation:
Given that,
The top of a roof is located 8.52 meters above the ground.
We need to find the time required for the shingles to reach the ground. Let the time be t. Its initial velocity was 0 as it was at rest initially. Using the equation of motion to find it as follows :
Where
t is the time and u = 0
So, it will take 1.31 seconds for the shingles to reach the ground.
Answer:
a) KE = 0.0857Joules
b) height = 0.073m
Explanation:
The rotational inertia of the rod at an axis passing through the fixed end is given by:
I = Icm + my
I= 1/12 mL^2 + m(L/2)
I= 1/12 ×0.12×(0.75)^2 + 0.12× (0.75/2)^2
I = 5.625×10^-3 + 0.01688
I = 0.0225Kg/m^-2
a) KE = 1/2 Iw^2
Where I= rotational inertia
w= angular speed at lowest point
KE = 1/2 × 0.0225 ×(2.76)^2
KE= 0.0857 Joules
b) Ki + Ui = Kf + Uf
Ki = Uf - Ui = 0
mgh = K
0.0857= mgh
h = 0.0857/( 0.120× 9.8)
h = 0.0857/ 1.176
h = 0.073m
Gravity is often assumed to be the same everywhere on Earth, but it varies because the planet is not perfectly spherical or uniformly dense. In addition, gravity is weaker at the equator due to centrifugal forces produced by the planet's rotation
