Question

On a double-well roller coaster, the person starts from a height of 10.5 meters, the height of the middle bump of the well is 6.7 meters. How much kinetic energy does this person have at the middle of the middle bump from the bottom if the mass of the person is 79 kg? (g=9.8 m/s2) Round to two decimal places.

Answer 1

Answer:

"2941.96 J" is the appropriate answer.

Explanation:

The given values are:

Mass,

m = 79 kg

Height,

h = 10.5 m

Now,

The total energy at the given height will be,

⇒ Potential energy = mgh

On substituting the values, we get

                                = $79\times 9.8\times 10.5$

                                $=8129.1 \ J$

So,

⇒ At height 6.7 m, total energy =  At height 10.5 m, total energy

On substituting the values, we get

⇒ $Potential \ energy+Kinetic \ energy=8129.1$      

⇒       $79\times 9.8\times 6.7+Kinetic \ energy=8129.1$

⇒                $5187.14+Kinetic \ energy=8129.1$

⇒                                   $K.E=8129.1-5187.14$

⇒                                   $K.E=2941.96 \ J$