A substance made up of only one type of element
Answer:
310 meters
Explanation:
Given:
v₀ = 0 m/s
t = 8.0 s
a = -9.8 m/s²
Find: Δy
Δy = v₀ t + ½ at²
Δy = (0 m/s) (8.0 s) + ½ (-9.8 m/s²) (8.0 s)²
Δy = -313.6
Rounded to two significant figures, the object fell 310 meters.
half-life? what do you mean
There's a short handy formula for that.
If the object is just dropped and not tossed, and it's not affected by air resistance on the way down, then the distance it falls in T seconds is
D = (1/2) (gravity) (T²)
For this problem . . .
176.4 m = (1/2) (9.8 m/s²) (T²)
Divide each side by (4.9 m/s²) :
T² = (176.4 m) / (4.9 m/s²)
T² = (36 s²)
Take the square root of each side:
<em>T = 6 seconds</em>
