Question

Another rock in Death Valley at the Racetrack traveled 55.3 meters during the observation period of nine years. a . What was the rock's average speed in feet per year? Round your answer to the nearest whole number. feet per year b . If a strong wind gives a stone an initial velocity of v 0 = 11 m / s , and the friction coefficient of stone on ice is μ = 0.14 , and g = 9.81 m / s 2 . Use the equation v 2 0 = 2 μ g S to find the stopping distance S for the stone. Round your answer to the nearest tenth.

Answer 1

Answer:

a) 20 feet per year

b) 44.1 m

Step-by-step explanation:

Given:

Distance traveled during the observation period = 55.3 meters

Observation period = 9 years

initial velocity of v₀ = 11 m/s

friction coefficient of stone on ice is μ = 0.14

g = 9.81 m/s²

also,

v₀² = 2μgS

Now,

1 m = 3.28084 ft

thus,

Total distance in feet = 55.3 × 3.28084 = 181.430452 ft

Average speed = $\frac{\textup{Distance}}{\textup{Time}}$

or

Average speed = $\frac{\textup{181.430452}}{\textup{9}}$

or

Average speed = 20.159 feet/year ≈ 20 feet per year

b) v₀² = 2μgS

substituting the values in the above equation, we get

11² = 2 × 0.14 × 9.81 × s

or

121 = 2.7468 × s

or

s = 44.051 ≈ 44.1 m