Answer:
8.8 cm
31.422 cm/s
Explanation:
m = Mass of block = 0.6 kg
k = Spring constant = 15 N/m
x = Compression of spring
v = Velocity of block
A = Amplitude
As the energy of the system is conserved we have

Amplitude of the oscillations is 8.8 cm
At x = 0.7 A
Again, as the energy of the system is conserved we have

The block's speed is 31.422 cm/s
Answer:
-4.5 m/s
Explanation:
Even without doing calculations, we know that a projectile has the same speed coming down as it did going up at the same height. Since it went up at 4.5 m/s, it returns down at -4.5 m/s.
To prove it with math, use the given information:
v₀ = 4.5 m/s
a = -9.8 m/s²
Δy = 0 m
Find: v
v² = v₀² + 2aΔy
v² = (4.5 m/s)² + 2 (-9.8 m/s²) (0 m)
v = -4.5 m/s
<h2><em>
The Answer to Youre Question:</em></h2>
<em>I think it is B.</em>
<em>I hope this helps.</em>