A team of eight dogs pulls a sled with waxed wood runners on wet snow (mush!). The dogs have average masses of 19.0 kg, and the loaded sled with its rider has a mass of 210 kg. (a) Calculate the magnitude of the acceleration starting from rest if each dog exerts an average force of 185 N backward on the snow. (b) What is the magnitude of the acceleration once the sled starts to move

Answer

given,

number of dog = 8

mass of each dog = 19 Kg

mass of sled = 210 Kg

average force = 185 Nss

a) writing all the horizontal force

force acting by dog - friction force = (M + 8m) a

8 F_d - μ m g = (M + 8m) a

assuming coefficient of friction of snow be μ = 0.14

8 x 185 - 0.14 x 210 x 9.8 = (210 + 8 x 19) x a

a = 3.29 m/s²

b) the kinetic friction of coefficient is less than static friction

hence, we can suggest that acceleration of the sled will increase once the sled start to move.

a > 3.29 m/s²