So the equation used in this problem is ΔX=V0*T+1/2AT^2 the X is the distance, v0 is initial velocity, T is time, and a is acceleration. So when we plug these values it we get: 108= 0•T+1/2•3•T^2,the 0•t disappears, and the 1/2•3 gets us 1.5, so we have 108=1.5T^2, then we divide 108 by 1.5 which gets us 72=t^2, and we then take the square root and get 8.49=T so the answer is 8.49 seconds.
D. 18 miles driven in a week
Answer:
The work done on the block by the spring as it accelerates the block is 4kx².
Explanation:
Let initial distance is x.
It was compressed three times farther and then the block is released, new distance is 3x.
The work done in compressing the spring is given by :


So, the work done on the block by the spring as it accelerates the block is 4kx².
EPE= 0.5 * spring constant * (extension)^2
Spring constant=EPE/0.5*extension^2
5J/0.5*0.5^2
=40N/m