Question

a roller coaster with a potential energy of 235,200 j sits at the top of a 30 m high hill. what is the mass of the roller coaster? (formula: pe = mgh)
800 kg
7,840 kg
8,000 kg
78,400 kg

Explanation:

Step1: Rearrange the formula for mass

Given \(PE = mgh\), we can solve for \(m\) by the formula \(m=\frac{PE}{gh}\). The acceleration due to gravity \(g = 9.8\ m/s^{2}\), \(PE=235200\ J\) and \(h = 30\ m\).

Step2: Substitute the values into the formula

Substitute the values into \(m=\frac{PE}{gh}\), we get \(m=\frac{235200}{9.8\times30}\).
First calculate \(9.8\times30=294\). Then \(m=\frac{235200}{294}\).

Step3: Calculate the value of \(m\)

\(\frac{235200}{294}=800\)

Answer:

800 kg