Question

A body ascends a slope with a speed of 10ms^-1. If 105 J of energy of the body is lost due to friction , the height to which the body will rise is (take g =10ms^-2)?

Answer 1

Let's assume that the body will reach a height of h,
So using the equation of conservation of energy we can say,
Total energy initially=Potential energy of the body at its highest point+ energy lost due to frictional force
Now,initial energy of the body=kinetic energy+ potential energy=`0.5*m*(10)^2`+0 (assuming it's initial potential energy at the point of beginning of journey to be zero)
And final energy will be mgh+105
Now equating both side we get,
h=`(50m-105)/(10*m)` or
`5-(105/10)*(1/m)`
So we can also get the idea from here that value of m should not be equal or less than 2.1 Kg or else h will be zero or negative i.e the body will not at all go up