Aglider is undergoing simple harmonic motion on a frictionless air track. when it is at position x = 0.30 m, its kinetic energy is half of its potential energy, k=12u. what is the amplitude of its simple harmonic motion?

For general projectile motion, when the projectile is at the highest point of its trajectory, its acceleration is zero? a)the horizontal and vertical components of its velocity are zero. b) its velocity is perpendicular to the acceleration. c)the horizontal component of its velocity is zero. d)its velocity and acceleration are both zero.

Will you chech and finish these for me, because i am stumped with them.

Why is it important always to use horizontal bars in unit fractions when performing unit conversions?