Question

answer the below fast pls thank u

Answer 1

Answer:

object of mass is 20 kg

5

4

3

1

Answer 2

Answer:

Explanation:

assuming potential energy at ground level =0

assuming the value of g=10m/s²

1)when the height of the object is 4m,kinetic energy (K.E)=0

  potential enrgy (P.E)= mgh = 20 ×10×4=800J

   Total energy =P.E + K.E = 800 +0 = 800 J

2) when the height is 3m,P.E= mgh = 20×10×3=600J

   for finding kinetic energy ,we can simply subtract P.E from total energy     as total energy is a constant throughout the motion.

  K.E=total mechanical energy - P.E = 800-600 =200 J

   another method is by:

 from height 4m to 3m,it travelled 1m distance.

 so ,s= 1m

 now intial velocity(u) at 4m height =0

  we have to find the final velocity at 3m height

   using the equation v²=u²+2as

   v²=0²+2×10×1 ⇒ v²=20

   substituting it in the equation of K.E=(1/2)mv²= (1/2)×20×20=200J

    hence proved by this method too

3)  when height is 2m,

  P.E=mgh = 20×10×2=400J

  K.E=total mechanical energy - P.E = 800-400=400 J

4) when height is 1m,

   P.E=mgh =20×10×1=200J

  K.E=total mechanical energy - P.E = 800-200=600 J

5) just above the ground means h=0m

so P.E.=mgh = 20×10×0= 0J

so K.E=total mechanical energy - P.E = 800-0=800 J

so   4          800          0         800

      3          600         200     800

      2          400         400     800

      1           200         600     800

just above  0            800      800

the ground

Hope this helps you

pls mark as brainiest

thanks :)