Question

Question #b2ebb

Answer 1

I got `2.6m`

Explanation:

I would say that the Elastic Potential Energy of the spring is converted into Kinetic Energy for the brick and so we have:
`1/2kx^2=1/2mv^2`
rearranging:
`v=xsqrt(k/m)=0.25sqrt(1250/1.5)=7.2m/s` which should be the velocity with which the brick leaves the spring.
Using Kinematics we have that:
`v_f^2=v_i^2=2ah`
where:
`v_f=0` at the top of the trajectory;
`v_i=7.2m/s`
`g=-9.8m/s^2` is the downwards acceleration of gravity;
`h` is the eight reached.
So we get:
`0=(7.2)^2-2*9.8h`
rearranging:
`h=(7.2)^2/(2*9.8)=2.6m`