L1 & L2: Understanding Speed, Distance, Time, & Velocity (7.7AB)

What is the formula to calculate average speed?

Answer explanation

The correct formula for average speed is \( \text{Average Speed} = \frac{\text{Total Distance}}{\text{Total Time}} \). This means average speed is calculated by dividing the total distance traveled by the total time taken.

If a car travels 150 kilometers in 3 hours, what is its average speed?

• 45 km/h

• 50 km/h

• 55 km/h

• 60 km/h

Answer explanation

To find the average speed, divide the total distance by the total time. Here, 150 km ÷ 3 hours = 50 km/h. Therefore, the average speed of the car is 50 km/h.

Which of the following best describes the difference between distance and displacement?

• Distance is a vector quantity, while displacement is a scalar quantity.

• Distance is the total path traveled, while displacement is the shortest path between two points.

• Distance is always greater than displacement, while displacement can be greater than distance.

• Distance includes direction, while displacement does not.

Answer explanation

The correct choice states that distance is the total path traveled, while displacement is the shortest path between two points. This highlights that distance measures the entire journey, whereas displacement focuses on the direct line between start and end.

Palmer completes a 400-meter track in 50 seconds. What is Palmer's average speed?

• 6 m/s

• 7 m/s

• 8 m/s

• 9 m/s

Answer explanation

To find average speed, divide the total distance by total time. Palmer runs 400 meters in 50 seconds. Average speed = 400m / 50s = 8 m/s. Thus, the correct answer is 8 m/s.

How does speed differ from velocity?

• Speed includes direction, while velocity does not.

• Speed is a vector quantity, while velocity is a scalar quantity.

• Speed is the rate of change of distance, while velocity is the rate of change of displacement.

• Speed is always constant, while velocity can change.

Answer explanation

Speed measures how fast an object moves regardless of direction, while velocity considers direction and is defined as the rate of change of displacement. Thus, speed is about distance, and velocity is about displacement.

In a simple investigation, a toy car travels 20 meters in 4 seconds. What is the average speed of the toy car?

• 3 m/s

• 4 m/s

• 5 m/s

• 6 m/s

Answer explanation

To find the average speed, divide the distance by the time. Here, average speed = 20 meters / 4 seconds = 5 m/s. Thus, the correct answer is 5 m/s.

Which scenario best illustrates the concept of displacement?

• A person walks 10 meters north, then 10 meters south.

• A car travels 100 kilometers on a circular track.

• A bird flies 5 kilometers east and then 5 kilometers west.

• A cyclist rides 20 kilometers in a straight line.

Answer explanation

Displacement refers to the shortest distance from the initial to the final position. The cyclist's 20 kilometers in a straight line represents a clear change in position, while the other scenarios involve returning to the starting point.

A cyclist travels 30 kilometers north and then 40 kilometers east. What is the total distance traveled?

• 50 km

• 60 km

• 70 km

• 80 km

Answer explanation

The cyclist travels 30 km north and 40 km east. The total distance is simply the sum of these two distances: 30 km + 40 km = 70 km. Therefore, the correct answer is 70 km.

A car moves with a constant speed of 60 km/h for 2 hours. What is the total distance covered by the car?

• 100 km

• 110 km

• 120 km

• 130 km

Answer explanation

To find the distance, use the formula: Distance = Speed × Time. Here, Speed = 60 km/h and Time = 2 hours. Thus, Distance = 60 km/h × 2 h = 120 km. Therefore, the total distance covered by the car is 120 km.

Which of the following statements is true about velocity?

• Velocity is a scalar quantity that only considers magnitude.

• Velocity is a vector quantity that considers both magnitude and direction.

• Velocity is always greater than speed.

• Velocity does not change with direction.

Answer explanation

The correct statement is that velocity is a vector quantity, meaning it has both magnitude and direction. This distinguishes it from speed, which is a scalar quantity that only considers magnitude.