Question

a body of weight 30 N falls freely from a height of 15m and burrows into sand through a distance of 0.5 m. find the resistance due to sand​

Answer 1

Answer:

√10/50

Step-by-step explanation:

mass=5kg,height=50m

v²=u²+2gh=0+2×50=980

v²=u²+2as0=980+2a(1)=-490m/s²

average resistance force offered by sand =ma=(-5)(490)=-2450N

time t=v-u/a0-10√10/-500 t=√10/50

Answer 2

Answer:

1. Step-by-step explanation:

given,  Weight=30N ,  height=15m  ,  Initial velocity = 0

assume g= 10m/s²

so, v² = u² + 2gh

v²= 0 + 2×10×15

v²=300m/s

v=√300 m/s

means, when object hit the sand then there velocity is √300 m/s

2. For second condition, question say that,

After hit the sand the object burrows through 0.5m, and stop

So , we have

u= √300m/s, v= 0m/s, h=0.5m  , retardation=?

so, v² = u² + 2ah

0=(√300)²+2×a×0.5

0=300+1a

a=-300m/s²

Now , question ask that resistance due to sand ,

Means, Friction Force

we know,  F= Mass × Acceleration

                  F=  3   ×  -300          ( w= mg, 30N=m×10, m= 3kg)

                  F= -900N

so, resitance due to sand is 900N.