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 17 s. How far has Jason traveled when he finally coasts to a stop?A.) 250 mB.) 350 mC.) 490 mD.) 660 m

Respuesta :

Answer:

Option D

660 m

Explanation:

ma=Thrust – friction where m is mass and a is acceleration

ma=200 - \mu mg

Substituting m for 75 kg, [tex]\mu[/tex] for 0.10, g for 9.81

75a=200 - 0.10*75*9.81

75a= 200-73.575

a=126.425/75

[tex]a = 1.685667 m/s^{2}[/tex]

For the first 17 seconds

Velocity v = a*t = 1.685667 17 = 28.65633 m/s

Distance = [tex]0.5*a*t^{2} = 0.5*1.685667*17^{2}[/tex] = 243.5788 m

After fuel is over

Force acting is only friction

[tex]F = ma = -\mu mg[/tex] since m are common

[tex]a = -\mu g = -0.1*9.81 = -0.981 m/s^{2}[/tex]

[tex]v^{2} - u^{2} = 2as[/tex]

Where v is final velocity which is zero because after running out of fuel, skis come to rest. U is initial velocity which is 28.65633 m/s

[tex]0 - 28.65633^{2} = 2*-0.981*s[/tex]

s = 418.5450765 m

Total distance = s1+s2 = 243.5788 m + 418.5450765 m m = 662.1239098 m

Distance covered is approximately 660 m