An 80-Kg Block Is Released from Rest,with V₁ = 0

Multiple Choice

An 8.0-kg block is released from rest,with v₁ = 0.00 m/s,on a rough incline,as shown in the figure.The block moves a distance of 1.6-m down the incline,in a time interval of 0.80 s,and acquires a velocity of v₂ = 4.0 m/s.How much work does gravity do on the block during this process?

A) +81 J
B) +100 J
C) +120 J
D) -81 J
E) -100 J