Answer:
B.6.86 m
Explanation:
Given that
Compression in spring ,x= 9 cm
Spring constant ,K= 830 N/m
Mass of the rocket ,m= 50 g = 0.05 kg ( 1 kg = 1000 g)
Now by applying energy conservation
[tex]\dfrac{1}{2}Kx^2=mgh[/tex]
[tex]h=\dfrac{1}{2\times mg}kx^2[/tex]
Now by putting the values ( we are taking g= 9.81 m/s²)
[tex]h=\dfrac{1}{2\times 9.81\times 0.05}\times 830\times 0.09^2[/tex]
h= 6.853 m
Therefore the answer is B.
B.6.86 m