From fastest to slowest, which of the following lists describes the speed at which sound tends to travel in different materials?

While water skiing behind her father’s boat, Letty is pulled at constant speed by a force of 164 N from the tow rope that makes

kap26 [50]

Answer:

0.265

Explanation:

Draw a free body diagram. There are four forces:

Normal force Fn pushing up.

Weight force mg pulling down.

Tension force T at an angle θ.

Friction force Fn μ pushing left.

Sum the forces in the y direction:

∑F = ma

Fn + T sin θ − mg = 0

Fn = mg − T sin θ

Sum the forces in the x direction:

∑F = ma

T cos θ − Fn μ = 0

Fn μ = T cos θ

μ = T cos θ / Fn

μ = T cos θ / (mg − T sin θ)

Given T = 164 N, θ = 10.0°, m = 65.0 kg, and g = 9.8 m/s²:

μ = (164 N cos 10.0°) / (65.0 kg × 9.8 m/s² − 164 N sin 10.0°)

μ = 0.265

7 0

3 years ago

What would be the coefficient of performance if the refrigerator (operating between the same temperatures) was instead used as a

viktelen [127]

Complete Question

A certain refrigerator, operating between temperatures of -8.00°C and +23.2°C, can be approximated as a Carnot refrigerator.

What is the refrigerator's coefficient of performance? COP

(b) What If? What would be the coefficient of performance if the refrigerator (operating between the same temperatures) was instead used as a heat pump? COP

Answer:

a

$COP = 8.49$

b

$COP_1 = 9.49$

Explanation:

From the question we are told that

The lower operation temperature of refrigerator is $T_1 = -8.00^oC = 265 \ K$

The upper operation temperature of the refrigerator is $T_2 = 23.2 ^oC = 296.2 \ K$

Generally the refrigerators coefficient of performance is mathematically represented as

$COP = \frac{T_1}{T_2 - T_1 }$

=> $COP = \frac{265}{296.2 - 265 }$

=> $COP = 8.49$

Generally if a refrigerator (operating between the same temperatures) was instead used as a heat pump , the coefficient of performance is mathematically represented as

$COP_1 = \frac{T_2}{ T_2 - T_1}$

=> $COP_1 = \frac{296.2}{ 296.2 - 265 }$

=> $COP_1 = 9.49$

8 0

3 years ago

3. A 142 g baseball is thrown at a speed of 42.9 m/s. What is the kinetic energy of the baseball at this moment?

krok68 [10]

Kinetic energy=1/2mv^2
=1/2(142*10^-3)(42.9)^2=130.6=131J

8 0

3 years ago

Briefly explain the difference between being self-centered and

tensa zangetsu [6.8K]

Answer:

Explanation:

Self centered means you think about yourself and can sometimes mean that you're arrogant. Self aware means you are aware of certain things you do. Self centered has a negative connotation while self aware has a positive one.

6 0

3 years ago

Read 2 more answers

The Zika Virus is most dangerous to which group of people?

laiz [17]

Answer:

option D pregnant women

4 0

4 years ago