Anybody know the answer to this physics problem?
A 300-g mass is attached to the bottom of a vertical spring, pulled downward and then released. The mass moves upward until it causes the spring to compress 5 cm. If the spring constant is 8.8 N/m, what acceleration is the mass experiencing at this position?

Basically I wrote
m = 0.3 kg
d = 0.05m
k = 8.8 N/m
a = ?

I knew that the spring force = 0.05 * 8.8 = 0.44 N
I knew that the force of gravity = 0.3 * 9.8 = 2.94 N

I knew that the net force = 0.44 N - 2.94 N = -2.5 N
I used the equation F=ma
-2.5 N = 0.3 kg * a
I got a = -8.33 m/s/s
But the webassign is saying that it is incorrect :( Please somebody help me!

Question

Anybody know the answer to this physics problem?
A 300-g mass is attached to the bottom of a vertical spring, pulled downward and then released. The mass moves upward until it causes the spring to compress 5 cm. If the spring constant is 8.8 N/m, what acceleration is the mass experiencing at this position?

Basically I wrote
m = 0.3 kg
d = 0.05m
k = 8.8 N/m
a = ?

I knew that the spring force = 0.05 * 8.8 = 0.44 N
I knew that the force of gravity = 0.3 * 9.8 = 2.94 N

I knew that the net force = 0.44 N - 2.94 N = -2.5 N
I used the equation F=ma 
-2.5 N = 0.3 kg * a
I got a = -8.33 m/s/s
But the webassign is saying that it is incorrect :( Please somebody help me!

jiteshmeghwal9 · Answer

the question is asking the acceleration after it compressed the spring by 5 cm

inkyvoyd · Answer

Can you draw an FBD? Are you sure the spring force and force of gravity are opposite in polarity?

steve816 · Answer

@inkyvoyd Yes, they are opposite 
@jiteshmeghwal9 So how would I calculate it???

inkyvoyd · Answer

Why don't you try drawing a picture first?

steve816 · Answer

|dw:1475829768076:dw|

Ok now what?