Question

normal
gravity
friction
acceleration
along the vertical.
at an angle parallel to the ramp.
at an angle perpendicular to the ramp.
not a force and should not be included.

Explanation:

• Normal force acts perpendicular to contact surface (ramp).
• Gravity acts vertically toward Earth's center.
• Friction opposes motion, parallel to ramp surface.
• Acceleration is a motion quantity, not a force.

Answer:

• Normal: At an angle perpendicular to the ramp.
• Gravity: Along the vertical.
• Friction: At an angle parallel to the ramp.
• Acceleration: Not a force and should not be included.