Answer:
E) True. The girl has a larger tangential acceleration than the boy.
Explanation:
In this exercise they do not ask us to say which statement is correct, for this we propose the solution to the problem.
Angular and linear quantities are related
v = w r
a = α r
the boy's radius is r₁ = 1.2m the girl's radius is r₂ = 1.8m
as the merry-go-round rotates at a constant angular velocity this is the same for both, but the tangential velocity is different
v₁ = w 1,2 (boy)
v₂ = w 1.8 (girl)
whereby
v₂> v₁
reviewing the claims we have
a₁ = α 1,2
a₂ = α 1.8
a₂> a₁
A) False. Tangential velocity is different from zero
B) False angular acceleration is the same for both
C) False. It is the opposite, according to the previous analysis
D) False. Angular acceleration is equal
E) True. You agree with the analysis above,
Answer:
The first is the closest in absolute values.
The second two are vague and the last is approximate.
Setting up an integral of
rotation is used as a method of of calculating the volume of a 3D object formed
by a rotated area of a 2D space. Finding the volume is similar to finding the
area, but there is one additional component of rotating the area around a line
of symmetry.
<span>First the solid of revolution
should be defined. The general function
is y=f(x), on an interval [a,b].</span>
Then the curve is rotated
about a given axis to get the surface of the solid of revolution. That is the
integral of the function.
<span>It all depends of the
function f(x), which must be known in order to calculate the integral.</span>
A) change in ht after 180m = 180 * sin(4-deg.) = 12.56m
net work done by gravity on the cyclist = mass * gravity * height diff.
= 85 * 9.8 * 12.56
= 10470J
= 10.5kJ
B) Kinetic energy = 1/2 * mass * vel.^2 = work done by gravity = 10470J
vel.^2 = 10470 * 2 / 85 = 246.4
vel. = 15.7m/s