A roller-coaster is at the top of a 62-meter hill. The car and its passengers have a total mass of 1,088 kilograms. By the time the car reaches the bottom of the hill, its speed is 74 miles per hour (33 meters per second). How much kinetic energy does the car have at the bottom of the hill?

KE=12mv2


(1 point)
Responses

592,416 J
592,416 J

2,978,944 J
2,978,944 J

1,184,832 J
1,184,832 J

17,952 J

1 answer

To calculate the kinetic energy (KE) of the roller-coaster car at the bottom of the hill, you can use the formula for kinetic energy:

\[ KE = \frac{1}{2} mv^2 \]

where:

  • \( m \) is the mass of the car and passengers (1,088 kg),
  • \( v \) is the speed of the car at the bottom of the hill (33 m/s).

Plugging in the values:

\[ KE = \frac{1}{2} \times 1088 , \text{kg} \times (33 , \text{m/s})^2 \]

Calculating \( (33 , \text{m/s})^2 \):

\[ 33^2 = 1089 , \text{m}^2/\text{s}^2 \]

Now, substituting this back into the kinetic energy equation:

\[ KE = \frac{1}{2} \times 1088 \times 1089 \]

Calculating \( \frac{1}{2} \times 1088 = 544 \):

\[ KE = 544 \times 1089 \]

Now performing the multiplication:

\[ KE = 544 \times 1089 = 591,936 , \text{J} \]

However, I notice that none of the answer choices match this exactly. The closest round number calculation could be interpreted in terms of significant figures or rounding errors, so let's check again:

Calculating directly,

\[ 544 \times 1089 \approx 592,416 , \text{J} \]

So the kinetic energy of the car at the bottom of the hill is:

\[ \boxed{592,416 , \text{J}} \]