Answer:
The velocity of the skateboard is 0.774 m/s.
Explanation:
Given that,
The spring constant of the spring, k = 3086 N/m
The spring is stretched 18 cm or 0.18 m
Mass of the student, m = 100 kg
Potential energy of the spring, [tex]P_f=20\ J[/tex]
To find,
The velocity of the car.
Solution,
It is a case of conservation of energy. The total energy of the system remains conserved. So,
[tex]P_i=K_f+P_f[/tex]
[tex]\dfrac{1}{2}kx^2=\dfrac{1}{2}mv^2+20[/tex]
[tex]\dfrac{1}{2}\times 3086\times (0.18)^2=\dfrac{1}{2}mv^2+20[/tex]
[tex]50-20=\dfrac{1}{2}mv^2[/tex]
[tex]30=\dfrac{1}{2}mv^2[/tex]
[tex]v=\sqrt{\dfrac{60}{100}}[/tex]
v = 0.774 m/s
So, the velocity of the skateboard is 0.774 m/s.
