Question

Along the remote Racetrack Playa in Death valley, California,stones sometimes gouge out prominent trails in the desert floor, asif they had been migrating. For years curiosity mounted about whythe stones moved. One explanation was that strong winds during theoccasional rainstorms would drag the rough stones over groundsoftened by rain. When the desert dried out, the trails behind thestones were hard-baked in place. According to measurements, thecoefficient of kinetic friction between the stones and the wetplaya ground is about 0.80. What horizontal force is needed on a26 kg stone (a typical mass) to maintainthe stone's motion once a gust has started it moving?

Answer 1

Answer:

Explanation:

given ;

• coefficient of kinetic friction = 0.80

• mass m = 26kg

• considering the force acting in horizontal direction and from newton's 2nd law of motion;

• for vertical motion = Fn - mg = 0

• for horizontal motion = F = ma + miu mg = m( a + miu.g)

• but a = 0

• therefore, F = miu mg where g = 9.81m/s^2

• plugging the values into the equation;

• F = 0.80 x 9.81 x 26

Horizontal force = 204.05N