Question

The K.E. of a body moving with a velocity of 10m/s
is 10J. What must be its velocity so that K.E. becomes
90J ?​

Answer 1

KE = 10J

v = 10m/s

Let, mass be m,

½mv² = 10

½m10² = 10

½m100 = 10

50m = 10

m = 10/50 = 1/5 = 0.2kg

Now Given,

KE = 90J

m = 0.2kg

Let the velocity be v',

½mv'² = 90

½×0.2 v'² = 90

0.1v'² = 90

v'² = 900

v' = 30m/s

Cheers!

Answer 2

Answer:

v = 90m/s

Explanation:

ke = 10 J v = 10m/s

then , ke = 90 J v = ?

v=

$(90 \times 10) \div 10$

v = 90 m/s

HOPE IT HELPS YOU !!☆☆☆