Map sapling leaming A heavy sled is being pulled by two pecple as shown in the f

Question

Map sapling leaming A heavy sled is being pulled by two pecple as shown in the figure. The coefficient of static friction between the sled and the ground is = 0.619, and the kinetic friction coefficient is = 0.467. The combined mass of the sled and its load is m-261 kg The ropes are separated by an angle 25°. and they make an angle -31.8" with the horizontal Assuming both ropes pull equally hard, what is the minmum rope tension required to get the sled moving? Number If this rope tension is maintained after the sled starts moving, what is the sled's acceleration? Number m/s

Explanation / Answer

Here,

coefficient of kinetic friction , uk = 0.467

theta = 31.8 degree

phi = 25 degree

m = 261 Kg

us = 0.619

let the minimum tension needed is T

combined tension , Ts = 2 * T * cos(phi/2)

Ts = 2 * T * cos(25/2)

Ts= 1.96 * T

Now, let the normal force is N

N = mg - Ts * sin(theta)

for just moving the sled

Ts * cos(theta) - us * N = 0

1.96 * T * cos(25) - 0.619 * (261 * 9.8 - 2 * T * sin(25)) = 0

solving for T

T = 688.5 N

the tension in the cable must be 688.5 N

b)

let the acceleration is a

for the net force

N * (us - uk) = m * a

(261 * 9.8 - 2 * 688.5 * sin(25)) * (0.619 - 0.467) = 261 * a

solving for a

a = 1.15 m/s^2

the angular acceleration is 1.15 m/s^2

Related Questions

Navigate

• Browse (All)
• Browse M
• Subjects

---