The resistivity of a metallic, single-walled carbon nanotube is 2.30 ✕ 10−8 Ω · m. The electron number density is 6.60 ✕ 1028 m−3. What is the mean free time for the electrons flowing in a current along the carbon nanotube?

  The mean free time is given as z  

Explanation:

Generally the formula for resistivity

Where

              is he resistivity of metal

               is the mass of the electron

               is the charge of the electron

              is  electron density

            is the mean free time

  Now making z the subject  of the formula

              =>  

    Substituting the given values

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards