Respuesta :
Kinetic energy = (1/2) (mass) (speed)²
The coaster's original kinetic energy was
KE = (1/2) (2,000 kg) (10 m/s)²
KE = (1,000 kg) (100 m²/s²)
KE = 100,000 kg-m²/s²
old KE = 100,000 joules
After something slowed it down, its new kinetic energy is
KE = (1/2) (2,000 kg) (6 m/s)²
KE = (1,000 kg) (36 m²/s²)
KE = 36,000 kg-m²/s²
new KE = 36,000 joules
The coaster lost (100,000 - 36,000) = 64,000 joules of KE.
Energy is conserved. It can't evaporate, disappear, or be destroyed.
That 64,000 joules had to go somewhere.
Someone or something had to do 64,000 joules of work on it in order to slow it down.
The work done by the external force on the roller coaster is 64000 J.
How do you calculate the work done on the roller coaster?
Given that the mass of The roller coaster is 2000 kg and its velocity is 10 m/s. The kinetic energy of the roller coaster is given below.
[tex]KE = \dfrac {1}{2}mv^2[/tex]
[tex]KE = \dfrac {1}{2}\times 2000\times (10)^2[/tex]
[tex]KE = 100000 \;\rm J[/tex]
Since the roller coaster has a force of unknown magnitude which decreases its speed to 6 m/s. For this decreased speed, the kinetic energy is given as below.
[tex]KE'= \dfrac {1}{2}mv'^2[/tex]
[tex]KE'= \dfrac {1}{2}\times 2000\times 6^2[/tex]
[tex]KE' = 36000\;\rm J[/tex]
The work done on the roller coaster is calculated by the change in the kinetic energy for both speeds.
Work Done = KE - KE'
Work = 100000 - 36000
Work = 64000 J
Hence we can conclude that the work done by the external force on the roller coaster is 64000 J.
To know more about the work, follow the link given below.
https://brainly.com/question/3902440.
