Question

In a ballistic pendulum experiment, projectile 1 results in a max height,h, of the pendulum equal to 2.6cm. A second projectile (of the same mass) causes the pendulum to swing twixe as high, h2 = 5.2cm. The second projectile was how many times faster than the first?

Answer 1

Are you familiar with the work kinetic energy formula and conservation of momentum?
you'll need them for this.