Question

a projectile can ____. include all that apply.
a. be on a surface
b. encounter air resistance
c. be moving upwards
d. be moving downwards
e. experience a balance of forces
f. have an overall constant speed

Explanation:

• A projectile is an object moving under gravity (with optional air resistance). It can be on a surface momentarily (like when launched or landing).
• Air resistance can be included in projectile motion analysis (real-world cases).
• Projectiles move upward during ascent and downward during descent.
• A projectile cannot have balanced forces (gravity/air resistance act, so net force is non-zero), meaning it accelerates, so speed cannot be constant overall.

Answer:

a. be on a surface
b. encounter air resistance
c. be moving upwards
d. be moving downwards