Question

Jason takes off from rest across level water on his jet-powered skis. The combined mass of Jason and his skis is 75 kg (the mass of the fuel is negligible). The skis have a thrust of 200 N and a coefficient of kinetic friction on water of 0.10. Unfortunately, the skis run out of fuel after only 75 s. What is Jason's top speed?

Answer 1

v = 126 m / s

Step-by-step explanation:

Let's analyze this exercise a little, they give us the thrust that is the applied force and the time that it lasts, and they ask us for the final speed, so we can use the Impulse ratio and the variation of the amount of movement

I = F t = Dp

F t = pf -p₀

Now let's use Newton's second law to find the net thrust

F = E - fr

the friction force has the formula

fr = μ N

let's write Newton's second law on the y-axis

N-W = 0

N = W

we substitute

fr = μ mg

we look for the net out

F = 200 - μ mg

With the skater starting from rest, the initial speed is zero (vo = 0)

we substitute

(200 - very m g) t = m v

v = (200 µm - very g) t

let's calculate

v = (200/75 - 0.10 9.8) 75

v = 126 m / s