Question) Solve this
 
When a body is projected vertically up from the ground, its potential energy and kinetic energy at a point P are in the ratio 1:5. If same body is projected with half the pervious velocity, then at the same point P, ratio of its potential energy and kinetic energy would be 
A. 1 : 2
B. 2 : 1
C. 1 : 5
D. 2 : 5

Dear student
Let H be the maximum height reached by thr body and h be the height above the ground where
P.E. : K.E. = 1:5
supposed it reached the point p
at p  energy is = K.E. + P.E.
           K.E. at point p = mgH-mgh = mg (H-h)
                  P.E.K.E.=mghmg(H-h)=15      hH-h=15           H = 6h
when body is projected upwards H=u22gwhen velocity becomes halfH' = (u2)22g=H4ratio of same potential and kinetic energy will be P.E.K.E.=hH'-h             = hH4-h               =h6h4-h=2  
  ratio = 2:1
Regards

  • -1

please resend it and turn it 90 degree(right to left side) as i am unable to read it like this

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