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:
a) v_Nort = 2.236 m / s
, θ = 56.3º, b) t= 53.76 s
Explanation:
This exercise should use the addition of vectors, we have a kayak speed of v₁ = 3 m / s and an eastward speed of water v₂ = 2.0 m / s.
They ask us to cross the river that is to the north, we see that the speed of the kayak is the hypotenuse of the triangula, see attached
v₁² = v_nort² + v₂²
v _nort² = v₁² –v₂²
v_nort = √ (3² - 2²)
v_Nort = 2.236 m / s
For the angle we can use trigonometry
tan θ = v₂ / v₁
θ = tan⁻¹ v₂ / v₁
θ = tan⁻¹ 2/3
θ = 33.7º
This angle measured from the positive side of the x axis is
θ = 90 - 33.7
θ = 56.3º
b) we look for the northward component of this speed
sin 56.3 = 
/ v_nort
v_{y} = v_nort sin 56.3
v_{y} = 2.236 sin 56.3
v_{y} = 1.86 m/s
The time is
v_{y} = y/t
t = y/v_{y}
t =100/ 1.86
t= 53.76 s
The combination of symbols that shows the ratio of elements
in a compound is called chemical formula. A chemical formula is one of the ways
in expressing information about the ratio and proportion of atoms that consists
a particular chemical compound. This is done by using a single line pf chemical
symbols of elements, numbers, and sometimes parentheses, comma, dashes,
brackets and sometimes the positive and negative sign. Chemical formula can
completely specify the simplest structure of molecules and chemical substances.
Answer:
A. Shear stresses are maximum at the neutral axis and normal stresses are maximum furthest from the neutral axis.
Explanation:
Normal stress :
Normal stress is defined as the stress or the restoring force that occurs on the plane when an external axial load is applied on it. For a beam the normal stress is maximum at the point furthest from the neutral axis and is zero at the neutral axis of the beam.
Shear stress :
Shear stress is a stress which occurs when the force acts on the surface of the member in a parallel direction. It changes the shape of the member. For a beam, the shear stress is maximum at the neutral axis.
