Answer:
a = 18.28 ft/s²
Explanation:
the values provided are:
duration of force application, t= 10 s
Work done = 10 Btu
mass of the object = 15 lb
acceleration, a =? ft/s²
1 Btu = 778.15 ft.lbf
thus, 10 Btu = 7781.5 ft.lbf

m = 0.466 slug
So,
the work is equivalent to the change in kinetic energy

The acceleration of the object is therefore


a = 18.28 ft/s²
the constant acceleration of the object is calculated to be 18.28 ft/s²