When the rocket reaches its maximum height, what is its kinetic energy?

In summary, a model rocket with a mass of 4.3kg is launched straight up at a speed of 65m/s. Its initial kinetic energy is 9083.75 J and its total energy is also 9083.75 J. At its maximum height, the rocket has a velocity of 0 and therefore its kinetic energy is 0. Its potential energy is now at maximum. This is because kinetic energy is the energy due to motion and at maximum height there is no motion, so all energy is converted to potential energy.
  • #1
laurenyntema
3
0
1. A model rocket with a mass of 4.3kg is launched straight up at a speed of 65m/s. Kinetic energy when it takes off is 9083.75 J. Total energy when it takes off is also 9083.75J. When the rocket reaches its maximum height, what is its kinetic energy?



2. KE(kinetic energy)=1/2MV^2



3. KE= 1/2(4.3)(65^2)
KE=1/2(4.3)(4225)
KE=1/2(18167.5)
KE=9083.75... not sure where to go from here...

 
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  • #2
Consider what its speed will be, just as it reaches the maximum height, and an instant before it begins to fall back down.
 
  • #3
To add to what mikelepore noted, remember that generally kinetic energy has to do with movement, and that with things like rockets and pendulums and such, the kinetic energy decreases as the potential energy increases. You're launching straight up, so you only have to worry about what's happening on a single axis.
 
  • #4
Ok, thanks!
I actually understand! Because kinetic energy is the energy due to motion, at maximum height the rocket would have a velocity of 0. Therefore, since there is actually no action taking place the kinetic energy is 0.
 
  • #5
Exactly :)

And conversely, it's potential energy is now at maximum.
 

Related to When the rocket reaches its maximum height, what is its kinetic energy?

1. What is kinetic energy?

Kinetic energy is a type of energy that an object possesses due to its motion. It is defined as the energy an object has because of its motion, and it depends on both its mass and velocity.

2. How is kinetic energy calculated?

Kinetic energy is calculated using the formula KE = 1/2 * m * v^2, where KE is kinetic energy, m is the mass of the object, and v is the velocity of the object.

3. What happens to the kinetic energy of a rocket when it reaches its maximum height?

When the rocket reaches its maximum height, its kinetic energy decreases. This is because its velocity decreases as it moves against the force of gravity.

4. Can the kinetic energy of a rocket be converted into other forms of energy?

Yes, the kinetic energy of a rocket can be converted into other forms of energy, such as potential energy or thermal energy. This conversion often occurs when the rocket is propelled by an engine or when it lands and its kinetic energy is absorbed by the ground.

5. Does the kinetic energy of a rocket vary during its flight?

Yes, the kinetic energy of a rocket varies during its flight. As the rocket accelerates, its kinetic energy increases and as it decelerates, its kinetic energy decreases. When it reaches its maximum height, its kinetic energy is at its lowest point.

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