Physics, 21.10.2019 22:30, jasmin2344

Find the coefficient of kinetic friction μk. express your answer in terms of some or all of the variables d1, d2, and θ.

Answers: 3

Show answers

Answers

answered: sierranowe2003

internet tension = mass * acceleration internet tension = 23 – Friction tension = 14 * acceleration Friction tension = µ * 14 * 9.8 = µ * 137.2 23 – µ * 137.2 = 14 * acceleration Distance = undemanding speed * time undemanding speed = ½ * (preliminary speed + very final speed) Distance = ½ * (preliminary speed + very final speed) * time Distance = 8.a million m, preliminary speed = 0 m/s, very final speed = a million.8 m/s 8.a million = ½ * (0 + a million.8) * t Time = 8.a million ÷ 0.9 = 9 seconds Acceleration = (very final speed – preliminary speed) ÷ time Acceleration = (a million.8 – 0) ÷ 9 = 0.2 m/s^2 23 – µ * 137.2 = 14 * 0.2 resolve for µ

answered: valeriestamann

μ_k = (d_1)*sin(Q) / [(cos(Q))*(d_1) + (d_2)]

Explanation:

On the slope:

- The force of gravity has magnitude "mg" and points points straight down the slope and is given by the expression:

F_g,down = m*g*sin(Q)

- The work done by gravity W_g is the dot product of F_g and the distance traveled d_1, shown:

W_g = F_g . d_1

W_g = m*g*sin(Q). d_1

- The normal Force F_n acts perpendicular to the slope and the gravity components also acts in the opposite to its direction, apply Equilibrium condition in the axis perpendicular to the slope since, their is no acceleration in that direction:

F_perp = F_n - F_g,up = 0

F_n = F_g,up = m*g*cos(Q)

- Since there is no work done in the direction perpendicular to slope its zero.

- Frictional force F_f acts parallel to the slope opposite in direction of motion, hence, directed up the slope is dependent on coefficient of friction u_k and normal contact force as follows:

F_f = u_k . F_n

F_f = u_k (m*g*cos(Q))

- The work done by friction W_f is the dot product of F_f and the distance traveled d_1, shown:

W_f = F_f . d_1

W_f = u_k*m*g*cos(Q). d_1

- So in summary, the total work done on the sled during the downhill phase is:

W_downhill = (m*g)*(d_1)*sin(Q) – (m*g)*(cos(Q))*(μ_k)*(d_1)

The horizontal terrain:

- Since, the Force of gravity (F_g) and normal force (F_n) both act perpendicular to the direction of motion, they do zero work.

- However, friction force (F_f) acts parallel to the direction of motion but opposite in direction, the work done by friction is:

W_f = F_f*d_2

W_f = u_k*F_n * d_2

W_f = - u_k * m*g*d_2

- So the total work done during the horizontal phase is:

W_hor = W_f = - u_k * m*g*d_2

Total Work done:

- So that means the total work done on the sled overall is:

W = W_downhill + W_hor

= (m*g)*(d_1)*sin(θ) – (m*g)*(cos(Q))*(μ_k)*(d_1) – (m*g)*(μ_k)*(d_2)

- The total work done is zero because the Kinetic energy at the start and end of the journey is zero.

(m*g)*(d_1)*sin(θ) – (m*g)*(cos(Q))*(μ_k)*(d_1) – (m*g)*(μ_k)*(d_2) = 0

- Simplify:

(d_1)*sin(Q) = (cos(Q))*(μ_k)*(d_1) + (μ_k)*(d_2)

(d_1)*sin(Q) = [(cos(Q))*(d_1) + (d_2)]*(μ_k)

- And then:

μ_k = (d_1)*sin(Q) / [(cos(Q))*(d_1) + (d_2)]

answered: Guest

(75°f − 32) × 5/9 = 23.889°c

answered: Guest

does anyone know or what?

Other questions on the subject: Physics

Physics, 22.06.2019 16:20, Kkgiddy

Iupil u5l aluve time remaining 01: 53: 45 ei and both agreed that childhood experiences play an important role in the development of oneself a sigmund freud alfred adler b. carl jung alfred adler c. carl jung erik erikson d. sigmund freud.. carl jung select the best answer from the choices provided save and exit next submit mark this and return

Answers: 1

continue

Physics, 22.06.2019 16:30, makennahudson94

In the nineteenth century, gregor mendel first determined some basic rules of genetics that have been observed throughout all types of life. no observations have disproved these basic rules of genetics. charles darwin developed the idea of biological evolution around the same time, but he was unaware of mendel’s discoveries in genetics. over a century later, darwin’s idea of evolution was modified in order to incorporate mendel’s rules of genetics along with the other evidence that darwin had used. what is most likely the relationship between mendel’s rules of genetics and darwin’s idea of biological evolution? a.)mendel’s genetics states laws that are now part of the theory of biological evolution. b.)biological evolution states laws that are part of mendel’s theory of genetics. c.)mendel’s genetics replaced darwin’s entire concept of biological evolution. d.)biological evolution is a law that explains why all genetics exist.

Answers: 1

continue

Physics, 22.06.2019 17:40, tylercapozzoli

Scientists follow specific processes in order to determine valid explanations and conclusions from observations. david observed strange lights in the sky above his home outside of roswell, new mexico. the only explanation that makes sense to him is that there are ufos in the area. what should david do next to verify his explanation?

Answers: 1

continue

Physics, 22.06.2019 18:30, jonathanvega424

Asmall 12.00g plastic ball is suspended by a string in a uniform, horizontal electric field with a magnitude of 10^3 n/c. if the ball is in equilibrium when the string makes a 30 ° angle with the vertical, what is the net charge on the ball?

Answers: 1

continue

Do you know the correct answer?

Find the coefficient of kinetic friction μk. express your answer in terms of some or all of the vari...