Question

Please answer this question of work energy and power

Answer 1

Answer:

Explanation:

if you treat block as a system

acceleration of system = 5m/sec^2

frictional force between surfaces for that acceleration = 45n

static frictional force = 9n

which exceeds more than static so apply kinetic on both surfaces

therefore acceleration of upper block = 17m/sec^2

acceleration of lower block = 0

frictional force between upper and lower = 6n

frictional force between lower and ground  = 6n

other method to do

Amax of 7kg block = 4/7m/sec^2

Asystem = 4/7

F-10 / 10 = 4/7

force upto which blocks move without relative sliding = 15.7