First, we will calculate the mass * 'm '* of the object.

Now, * *** Kinetic energy ** = ^{ 1 }/_{ 2 } mv^{ 2 }

So, 25 = ^{ 1 }/_{ 2 } x m x (5)^{ 2 }

25 = ^{ 1 }/_{ 2 } x m x 25

m = 2kg

When the velocity of the object is doubled, it becomes 5 x 2 = 10 m s ^{ -1 }

Now, ** *** Kinetic energy * = ^{ 1 }/_{ 2 } mv^{ 2 }

= ^{ 1 }/_{ 2 } x m x (10)^{ 2 }

= ^{ 1 }/_{ 2 } x 2 x 100

= 100 J

Thus, when the velocity of the object is doubled, then it 's ** ***Kinetic energy * becomes 100 J.

When the velocity of the object is increased three times, it becomes 5 x 3 = 15m s ^{-1 }

Now, ** *** Kinetic energy * = ^{ 1 }/_{ 2 } mv^{ 2 }

= ^{ 1 } ^{ }/ _{ 2 } x m x (15) ^{2}

= ^{ 1 } ^{ }/ _{ 2 } x 2 x 225

= 225 J

Thus, when the velocity of the object is increased three times,then it 's ** ***Kinetic energy * becomes 225 J.

HOPE IT HELPS U..........