A4 kilogram cat is resting on top of a bookshelf that is 3 meters high what is the cats gravitational potential energy relative to the floor if the acceleration due to gravity is 9.8m/s a.7j b. 29j c.12j d.118j

GPE = mgh

Where GPE is gravitational potential energy (J), m is the mass ob the object (kg), g is acceleration due to gravity (m/s²) and h is the height (m)

m = 4 kg
g = 9.8 m/s²
h = 3 m

By substitution,
GPE =  4 kg x 9.8 m/s² x 3 m
        = 117.6 J
        ≈ 118 J

Hence, the answer is D

The activity series is shown in the attached picture. if the element is below the other, then you can displace the other. following the activity series as a guide, the reactions are as follows: nickel and aluminum chloride3 ni + 2 alcl₃  → 3 nicl₂ + 2 albarium and copper bromideba + cubr  →  no reaction because cu is less oxidizable than bapotassium nitrate and aluminum3 kno₃ + al  → al(no₃)₃ + 3 ksodium phosphate and zincnaso₄ + zn  → znso₄ + na

Ions gain or lose electrons