Answer:
if Josh ate 1/4 of a pizza what's the fraction of the pizza is left
Mechanical energy E = mgh + 1/2mv²
When he starts, let h = 0 ⇒ E₁ = 1/2mv₁²
When he reaches height h ⇒ E₂ = mgh + 1/2mv₂²
Without friction, energy is conserved at all times.
E₁ = E₂
↓
1/2mv₁² = mgh + 1/2mv₂²
↓
1/2v₁² = gh + 1/2v₂²
↓
gh = 1/2(v₁² - v₂²)
↓
h = (v₁² - v₂²) / (2g)
Answer:
W'=125.44 N
Explanation:
The weight of a person on the surface of Earth is 784 N
Weight is given by :
W = mg
m is mass of the person and g is acceleration due to gravity on the surface of Earth (10 m/s²)

The acceleration due to gravity on the surface of Moon, g' = 1.6 m/s²
Weight of the person on the moon is :
W'=mg'

Hence, the person would weigh 125.44 N on the Moon.