Question

slove no 16 numerical​

Answer 1

Answer:

Explanation:

i) workdone by boy =  force * distance

    Weight = Mass * Gravitaional Field strength

                 = 20 kg * 9.8 [1 litre = 1kg]

                  = 196N

∴ WD = 196N * 20m

          = 3920 J

WD by father = 196N * 20m

                      = 3920 J

∴ Ratio = 3920 : 3920

            = 1 : 1

ii)  Power of boy = $\frac{WD}{T}$

                          = 3920/(3 * 60 seconds)

                          = 21.77 W

P of father =3920/(2 * 60 seconds)

                 =32.66W

∴ Ratio = 21.777 : 32.666

             =2 : 3

b) workdone by boy =  force * distance

    Weight = Mass * Gravitaional Field strength

                 = 20 kg * 9.8 [1 litre = 1kg]

                  = 196N

∴ WD = 196N * 20m

          = 3920 J

WD by father = 196N * 20m

                      = 3920 J or 3.92 kJ