High School

A roller coaster with a potential energy of [tex]235,200 \, J[/tex] sits at the top of a 30 m high hill. What is the mass of the roller coaster?

(Formula: [tex]P E = m g h[/tex])

A. 800 kg
B. 7,840 kg
C. 8,000 kg
D. 78,400 kg

Answer :

To find the mass of the roller coaster, you can use the formula for potential energy:

[tex]\[ PE = m \cdot g \cdot h \][/tex]

Where:
- [tex]\( PE \)[/tex] is the potential energy (given as 235,200 J),
- [tex]\( m \)[/tex] is the mass of the roller coaster (which we are solving for),
- [tex]\( g \)[/tex] is the acceleration due to gravity (approximately 9.81 m/s²),
- [tex]\( h \)[/tex] is the height (given as 30 m).

To solve for the mass [tex]\( m \)[/tex], we rearrange the formula:

[tex]\[ m = \frac{PE}{g \cdot h} \][/tex]

Plug in the given values:

[tex]\[ m = \frac{235,200}{9.81 \cdot 30} \][/tex]

Simplify the calculation:

[tex]\[ m = \frac{235,200}{294.3} \][/tex]

[tex]\[ m \approx 799.18 \text{ kg} \][/tex]

Rounding this to the nearest whole number, the mass of the roller coaster is approximately 800 kg.

Therefore, the closest answer from the options provided is 800 kg.