Please help ASAP. A 1.65 m tall student throws a 0.055 kg paper airplane directly vertically into the sky. It ends up travelling 12.3 m straight upwards. What is the potential energy of the paper airplane at the peak of its flight with respect to the ground?

During your summer internship for an aerospace company, you are asked to design a small research rocket. the rocket is to be launched from rest from the earth's surface and is to reach a maximum height of 910 m above the earth's surface. the rocket's engines give the rocket an upward acceleration so it moves with acceleration of 16.0 m/s2 during the time t that they fire. after the engines shut off, the rocket is in free fall. ignore air resistance.

Which of the following is a measure of the amount of light a star directly emits?               a.  luminosity    b.  intensity    c.  wavelength    d.  brightness

Determine the largest intensity w of the uniform loading that can be applied to the frame without causing either the average normal stress or the average shear stress at section b–b to exceed σ=19 mpa and τ=24 mpa, respectively.