Question

question 1 (2 points)
listen
a ball is thrown straight up in the air. at the top of its arc,
the energy is all kinetic
the energy is zero
the energy is all potential
the energy is infinite
question 2 (2 points)
listen
an airplane flies at constant horizontal velocity. the work done by the thrusting force must be
greater than the work done by the drag force
equal to the work done by the drag force
less than the work done by the drag force
zero

Explanation:

For Question 1, when a ball is thrown straight up and reaches the top of its arc, its velocity is 0 (momentarily stops moving up), so kinetic energy ($KE=\frac{1}{2}mv^{2}$) is 0. It has height above the ground, so it has gravitational potential energy ($PE = mgh$). Thus, the energy is all potential.
For Question 2, since the airplane is flying at a constant horizontal velocity, its acceleration in the horizontal direction is 0 according to Newton's first - law. The net force in the horizontal direction is 0. If the thrust force is $F_T$ and the drag force is $F_D$, then $F_{net,x}=F_T - F_D=0$. Work is $W = Fd\cos\theta$. For the same displacement $d$ in the horizontal direction, the work done by the thrust force $W_T=F_Td$ and the work done by the drag force $W_D = F_Dd$. Since $F_T = F_D$, the work done by the thrusting force is equal to the work done by the drag force.

Answer:

Question 1: The energy is all potential
Question 2: equal to the work done by the drag force