Question

A man pushes a block of 30 Kg along a level floor at constant speed with a force directed at 45° below the horizontal. If the coefficient of friction is 0.20, then:work done by all the forces exerted by the surface on the block in 20 meters is -1500 J. true Or false explain​

Answer 1

Answer

false

explanation

as net force = F cos 45 °

                    = u mg 1/√2

                   = 0.2 × 30 × 10 × 1/√2

                   = 30 √2

                   = 42.3 N

now work done = F cos Ф 20

                          = 42.3 × 20

                           = 846 J