A uniform ladder of length 10.0 m and mass 16.0 kg is resting against a vertical smooth wall making an angle of `37^@` with it. An electrian weighing 60.0 kg climbs up the ladder. If the stays on the ladder at a point 8.00 m from the lower end, what will be normal force and the force of friction on the ladder by the ground? What should be the minimum coefficient of friction for the electrician to work safely?

Answer

A, B, C, D

Explanation

`R_1=mR_2`
`R_2=16g+60g=745N`
`R_1xx10cos37^@=16gxx5sin37^@+80gx8xxsin37^@`

`rarr 8R_1=48g+288g`
`rarr R_1=(336g)/8=412N`
`Therefore mu=R_1/R_2=412/745=0.553`