A60-kg skier starts from rest from the top of a 50-m high slope. if the work done by friction is -6.0 kj, what is the speed of the skier on reaching the bottom of the slope? a 60-kg skier starts from rest from the top of a 50-m high slope. if the work done by friction is -6.0 kj, what is the speed of the skier on reaching the bottom of the slope? 17 m/s 31 m/s 28 m/s 24 m/s

31 m/s

Step-by-step explanation:

In order to find the speed of the skier at the bottom of the slope, you have to apply the Work-Energy Principle for mechanical energy.

W ncf= ΔEm

Where ΔEm is the variation of mechanical energy between two points of the displacement and Wncf is the work of all non-conservative forces.

The only non-conservative force producing work is the friction force. The normal force doesn't produce work because it's perpendicular to the displacement.

The variation of the mechanical energy can be considered from the top to the bottom of the slope.

Wncf= Emf-Emi

Where Emf is the final mechanicl energy and Emi is the initial mechanical energy.

The mechanical energy is defined by:

Em= Ep+Ek

Where Ep is the potential energy and Ek is the kinetic energy.

At the top of the slope, there's only potential gravitational energy (the kinetic  energy is zero because the skier starts from rest)

Emi=Ep= mgh

m=60 kg, g=9.8 m/s² and h=50 m

Emi= 29400 J

At the bottom of the slope, there's only kinetic energy (the potential gravitational energy is zero because the height is zero)

Emf= Ek = 1/2mv² =30v²

where v is the speed and m is the mass.

Replacing in the equation:

-6.0 = 30v² - 29400

Solving for v (Adding 29400, dividing by 30, extracting the square root)

v=31.3 m/s

answer:   segregation violated the equal protection clause of the 14th amendment, which holds that no state can “deny to any person within its jurisdiction the equal protection of the laws.”

details/explanation:

brown v. board of education of topeka, decided by the us supreme court in 1954, ruled that all americans are entitled to the same civil liberties and protections in regard to access to education. until that decision, it was legal to segregate schools according to race, so that black students could not attend the same schools as white students.   an older supreme court decision, plessy v. ferguson (1896), had said that separate, segregated public facilities were acceptable as long as the facilities offered were equal in quality.   in the case of brown v. board of education, that standard was challenged and defeated.   segregation was shown to create inequality, and the supreme court unanimously ruled segregation to be unconstitutional.

the ruling was important in advancing civil rights because it affirmed that the 14th amendment applies to all rights and privileges of citizens, including access to   education.   this was being violated by states whose laws supported the segregation of schools.   section 1 of the 14th amendment reads as follows:

$9.89

step-by-step explanation:

9.90 = p x .06 x .25 (3/12 changed to a decimal)

9.90 = p x 0.015

9.90 - 0.015 = p

9.89 = p