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Vlad1618 [11]
3 years ago
7

A roller coaster speeding down a hill is an example of

Physics
1 answer:
Debora [2.8K]3 years ago
3 0

Answer:

If I'm not wrong; I think the answer is A

Explanation:

A. Increasing kinetic energy

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Which describes the adiabatic process? Check all that apply.
kiruha [24]

Answer:

heat is not absorbed by the system

A rapid shift occurs between gas compression and expansion.

All heat is transformed to work done by the system.

Explanation:

7 0
4 years ago
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Find the shear stress and the thickness of the boundary layer (a) at the center and (b) at the trailing edge of a smooth flat pl
melomori [17]

Answer:

a) The shear stress is 0.012

b) The shear stress is 0.0082

c) The total friction drag is 0.329 lbf

Explanation:

Given by the problem:

Length y plate = 2 ft

Width y plate = 10 ft

p = density = 1.938 slug/ft³

v = kinematic viscosity = 1.217x10⁻⁵ft²/s

Absolute viscosity = 2.359x10⁻⁵lbfs/ft²

a) The Reynold number is equal to:

Re=\frac{1*3}{1.217x10^{-5} } =246507, laminar

The boundary layer thickness is equal to:

\delta=\frac{4.91*1}{Re^{0.5} }  =\frac{4.91*1}{246507^{0.5} } =0.0098 ft

The shear stress is equal to:

\tau=0.332(\frac{2.359x10^{-5}*3 }{1}  )(246507)^{0.5} =0.012

b) If the railing edge is 2 ft, the Reynold number is:

Re=\frac{2*3}{1.215x10^{-5} } =493015.6,laminar

The boundary layer is equal to:

\delta=\frac{4.91*2}{493015.6^{0.5} } =0.000019ft

The sear stress is equal to:

\tau=0.332(\frac{2.359x10^{-5}*3 }{2}  )(493015.6^{0.5} )=0.0082

c) The drag coefficient is equal to:

C=\frac{1.328}{\sqrt{Re} } =\frac{1.328}{\sqrt{493015.6} } ==0.0019

The friction drag is equal to:

F=Cp\frac{v^{2} }{2} wL=0.0019*1.938*(\frac{3^{2} }{2} )(10*2)=0.329lbf

7 0
3 years ago
Can someone help with physics
Naily [24]

Answer:

50m/s, 187.5m

Explanation:

Consider unit analysis:

m/s² = m/(s×s)

This can be read as "meters per second, per second". From fundamental kinematics, meters per second is the same as saying velocity.

Velocity is being increased per second, and this is called acceleration:

a = v/t, where a is acceleration, v is change of velocity and t is change of time. "Change" is represented by a triangle called delta and (delta)A = A2 - A1

From the question, we have the variables:

a = 5m/s²

(delta)v = v2 - 25m/s

(delta)t = 5s (initial time is 0)

a = v/t

(5m/s^2)=v/5s

25m/s = v2 - 25m/s

50m/s = v2

The final velocity of the vehicle is 50m/s.

A formula exists to find displacement with regards to acceleration:

d=v(initial) × t +1/2 × a × t²

d=25m/s × 5s + 1/2 × 5m/s² ×(5s)²

d=125m+1/2×125m

d=125m+62.5m

d=187.5m

The distance travelled by the vehicle is 192.5m.

<em>One of the most important skills you can have in any science is unit analysis. Treat meters, seconds, moles, etc as </em><em>values</em><em> when doing </em><em>calculations</em><em> </em><em>and see if you get the result you're looking for.</em>

7 0
3 years ago
Compare positive and negative feedback mechanisms.
NeX [460]

Answer:

In positive feedback mechanism, the output is fed back to the system which further increases the output. Hence, it is known as positive feedback because it amplifies the output.

In the negative feedback mechanism, the output is fed back to the system which further decreases the the output. Hence, it is known as negative feedback because it reduces the output.

6 0
4 years ago
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Maria listed four important points about Einstein’s special theory of relativity. 1) applies to any object moving more slowly th
DiKsa [7]
<span> applies to any object moving more slowly than the speed of light</span>
6 0
3 years ago
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