Question

5 which of the following describes a vehicle moving at a constant velocity? a a go - cart races at 50 km / hr around a circular track. b a bicycle slows down as it approaches an intersection. c a truck travels north at 70 km / hr on a straight road. d a car steadily speeds up after a traffic light turns green.

Explanation:

Velocity is a vector quantity, which means it has both magnitude (speed) and direction. For an object to have a constant velocity, both its speed and direction must remain unchanged.

• Option A: The go - cart is moving around a circular track. Although its speed is \(50\ km/hr\), its direction is constantly changing (since it's moving in a circle). So, its velocity is not constant.
• Option B: The bicycle is slowing down. Its speed is changing (decreasing), so its velocity is not constant.
• Option C: The truck is traveling on a straight road (constant direction) at a speed of \(70\ km/hr\) (constant magnitude of velocity). So, its velocity is constant.
• Option D: The car is speeding up. Its speed is changing (increasing), so its velocity is not constant.

Answer:

C. A truck travels north at \(70\ km/hr\) on a straight road.