homework and exercises - Acceleration during collision with ground

For my physics class, I have to calculate an objects acceleration while it came to a stop. It was traveling at $6.26\: \mathrm{\frac{m}{s}}$ at impact, and travels a distance of $0.025\: \mathrm{m}$ while stopping. I assumed I would use a simple kinematics equation to solve.

$$V_f^2 = V_i^2 + 2a\varDelta d$$

$$0 = 6.26^2 + 2*a*.025$$ $$-39.2 = .05a$$ $$a = -784\: \mathrm{\frac{m}{s^2}}$$ Is that right? It seems extremely high.