Suppose the ski patrol lowers a rescue sled and victim, having a total mass of 8

Question

Suppose the ski patrol lowers a rescue sled and victim, having a total mass of85.0kg, down a?=52.0 slope at constant speed, as shown in Figure 6.22. The coefficient of friction between the sled and the snow is 0.100.

Suppose the ski patrol lowers a rescue sled and victim, having a total mass of85.0kg, down a?=52.0 slope at constant speed, as shown in Figure 6.22. The coefficient of friction between the sled and the snow is 0.100. a) How much work is done by friction as the sled moves30.0m along the hill? 1541.7 J (b) How much work is done by the rope on the sled in this distance? - 19732 .5 J (c) What is the work done by gravity on the sled? J (d) What is the total work done? 0 J

Explanation / Answer

a) Workdone by friction, Wf = Ff*d*cos(180)

= mue_k*m*g*cos(58)*d*(-1)

= -0.1*85*9.8*cos(58)*30

= -1324 J

b) as the sled is moving with constant speed net force acting sled chould be equal to zero

Fnet = 0

T + Friction - m*g*sin(58) = 0

T = m*g*sin(58) - Friction

= 85*9.8*sin(58) - 0.1*85*9.8*cos(58)

= 662.3 N

so, workdone by tension, WT = T*d*cos(180)

= -662.3*30

= -19869 J

c) workdone by gravity = m*g*d*sin(58)

= 85*9.8*30*sin(58)

= 21193J

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.