Question

true or false
true false the horizontal motion of a projectile is constant
true false the vertical velocity at the highest point is the maximum velocity
true false a projectile experiences downward acceleration due to gravity
true false the horizontal motion of projectile depends on the vertical motion
true false the vertical velocity of a straight projectile is increasing downward
true false a ball rolling on the table is a projectile
true false all projectiles are not affected by air resistance

Explanation:

• First statement: In projectile motion, horizontal acceleration \(a_x = 0\) (assuming no air - resistance). Using the equation \(v_x=v_{0x}+a_xt\), with \(a_x = 0\), \(v_x = v_{0x}\) (constant).
• Second statement: At the highest point of a projectile, the vertical velocity \(v_y = 0\) (not maximum). The vertical motion is affected by gravity (\(a_y=-g\)).
• Third statement: The only force acting on a projectile (neglecting air - resistance) is gravity \(F = mg\) acting downwards. By \(F = ma\), \(a = g\) (downward).
• Fourth statement: Horizontal motion (\(x = v_{0x}t\)) and vertical motion (\(y=v_{0y}t-\frac{1}{2}gt^{2}\)) are independent. The time \(t\) is common, but one does not depend on the other's displacement/velocity in terms of the equations of motion.
• Fifth statement: For vertical motion, \(v_y=v_{0y}-gt\) (upward is positive). As the projectile moves down (\(t\) increases after reaching the highest point), \(v_y= - gt\) (magnitude increases as \(t\) increases, direction is downward).
• Sixth statement: A projectile is an object in free - fall (only force is gravity). A ball rolling on a table has a normal force from the table (\(F_N\)) counteracting gravity, so it is not in free - fall.
• Seventh statement: In reality, air - resistance (\(F_{air}=\frac{1}{2}

ho C_dAv^{2}\)) acts on projectiles. The assumption of no air - resistance is a simplification for basic projectile motion problems.

Answer:

1. TRUE
2. FALSE
3. TRUE
4. FALSE
5. TRUE
6. FALSE
7. FALSE