Question

the truck is described as travelling at 30mph to the west. the quantity described here is a(n)
a speed
b velocity
c acceleration
d kinetic energy

Explanation:

To solve this, we analyze each option:

• Option A (speed): Speed is a scalar quantity (only magnitude). But the truck's motion has a direction (west), so it's not just speed.
• Option B (velocity): Velocity is a vector quantity, meaning it has both magnitude (30 mph) and direction (west). This matches the truck's description.
• Option C (acceleration): Acceleration is the rate of change of velocity, which isn't described here (no change in speed or direction mentioned).
• Option D (kinetic energy): Kinetic energy depends on mass and speed (scalar), and there's no mass or energy - related info here.

Answer:

B. velocity