Question

question #3
reference q.46801
which of the following are expressed as vectors? which are scalars?
a. speed
b. velocity
c. energy
d. distance
e. displacement
f. force
g. time
h. mass
i. weight
j. height

Explanation:

To determine if a quantity is a vector or scalar, we use the definitions:

• Scalar: A quantity with only magnitude (e.g., speed, energy, distance, time, mass, height).
• Vector: A quantity with both magnitude and direction (e.g., velocity, displacement, force, weight).

Analysis of Each Quantity:

• a. Speed: Only magnitude (e.g., 5 m/s), so scalar.
• b. Velocity: Magnitude + direction (e.g., 5 m/s north), so vector.
• c. Energy: Only magnitude (e.g., 10 J), so scalar.
• d. Distance: Only magnitude (e.g., 10 m), so scalar.
• e. Displacement: Magnitude + direction (e.g., 10 m east), so vector.
• f. Force: Magnitude + direction (e.g., 5 N upward), so vector.
• g. Time: Only magnitude (e.g., 5 s), so scalar.
• h. Mass: Only magnitude (e.g., 2 kg), so scalar.
• i. Weight: Magnitude + direction (force due to gravity, e.g., 19.6 N downward), so vector.
• j. Height: Only magnitude (e.g., 2 m), so scalar.

Answer:

• Vectors: b. Velocity, e. Displacement, f. Force, i. Weight
• Scalars: a. Speed, c. Energy, d. Distance, g. Time, h. Mass, j. Height