Suppose an automobile has 3300 J of kinetic energy. When it moves at twice the speed, what will be its kinetic?
Hghsd asked:
Suppose an automobile has 3300 J of kinetic energy. When it moves at twice the speed, what will be its kinetic energy?
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Suppose an automobile has 3300 J of kinetic energy. When it moves at twice the speed, what will be its kinetic energy?
What’s its kinetic energy at three times the speed?
January 13th, 2010 at 11:18 am
Four times for twice the speed.
Nine times for three times the speed.
Since, kinetic energy =1/2*mv²,Then, velocity is increased “m” times kinetic energy becomes “m²” times kasab
January 13th, 2010 at 11:37 am
KE is proportional to the square of the velocity, therefore if the speed is doubled, the KE is increased by a factor of four. 13200 J Polyhymnio
January 13th, 2010 at 2:37 pm
kinetic energy depends on mass and square of the velocity
so When it moves at twice the speed its kinetic energy will become 4 times the 1st one
i.e. 13200J
and its kinetic energy at three times the speed will be three times the 1st one
ie19800J
………………., lucky me
January 16th, 2010 at 8:11 am
The first poster is correct. Here’s why:
Kinetic energy of an object is equal to K = .5mv^2, where m is mass and v is velocity.
If you assume that originally, the automobile is moving at 1v, K = 3300 J, or
K = 3300 J = .5m(1v)^2 = .5mv^2
If you double the speed, or make the automobile travel at 2v,
K = .5m(2v)^2 = .5m4v^2 = 2mv^2
This is FOUR times as much as when the automobile traveled at 1v. Therefore, the automobile will have 4*3300 = 13200 J of kinetic energy. If the automobile moves at 3v,
K = .5m(3v)^2 = .5m9v^2 = 4.5mv^2
That’s NINE times as much as when the automobile traveled at 1v. Therefore, the automobile will have 9*3300 = 29700 J of kinetic energy.
Sure, it’s useful to know the answer, but what’s more important is to know the METHOD behind it.
Hope this helps! Johnny Y
January 17th, 2010 at 12:39 am
The kinetic energy =1/2*mv².
So when velocity is increased ‘n’ times kinetic energy becomes n² times
When the auto moves twice the speed KE is quadrupled and when it moves at thrice the speed it is 9KE Sniper