Answer:
1176 J
Step-by-step explanation:
You want to know the potential energy of a sled of mass 30 kg up a slope 4 m high.
Potential energy
The given formula is ...
PE = mgh
Putting the given numbers into the formula, we have ...
PE = (30 kg)(9.8 m/s²)(4 m) = 1176 kg·m²/s²
PE = 1176 J
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Additional comment
A joule (J) is a derived SI unit of energy equivalent to 1 kg·m²/s².
"m" is used to represent two different things in this problem. In "mgh" it represents mass. In "4 m" and "m²/s²", it represents meters.