Unit test Review

Benjamin is measuring the temperature of a room. What kind of quantity is temperature?

• A quantity with direction

• A quantity without direction

• A quantity that is always positive

• A quantity that varies with time

Answer explanation

Temperature is a scalar quantity, meaning it has magnitude but no direction. This distinguishes it from vector quantities, which do have direction. Therefore, the correct choice is 'A quantity without direction'.

Avery is pushing a shopping cart at the grocery store. Which of the following quantities related to the cart is a vector quantity?

• Temperature

• Mass

• Force

• Time

Answer explanation

Force is a vector quantity because it has both magnitude and direction, which is essential when pushing a cart. In contrast, temperature, mass, and time are scalar quantities, lacking direction.

Arjun is driving his car on a highway. He wants to calculate his speed. Which of the following formulas should he use?

• Speed = Distance / Time

• Speed = Displacement / Time

• Speed = Distance × Time

• Speed = Time / Distance

Answer explanation

The correct formula to calculate speed is Speed = Distance / Time. This formula shows that speed is determined by dividing the total distance traveled by the time taken to travel that distance.

Liam is running a race. What is the unit of speed?

• m/s

• m/s²

• m

• s

Answer explanation

The unit of speed is meters per second (m/s), which measures distance traveled in meters over time in seconds. Other options like m/s² (acceleration), m (distance), and s (time) do not represent speed.

Mia is riding her bicycle and notices that her speed increases as she pedals harder. Acceleration is defined as:

• The change in speed per unit time

• The distance traveled in a certain time

• The total distance covered

• The speed of an object

Answer explanation

Acceleration is defined as the change in speed per unit time, which explains why Mia's speed increases as she pedals harder. The other options do not accurately describe acceleration.

Elijah and Aiden are running a race. Elijah runs in a straight line towards the finish line, while Aiden runs around the track. What is the difference between speed and velocity?

• Speed is faster than velocity

• Velocity includes direction; speed does not

• Velocity is always constant

• Speed is a vector quantity

Answer explanation

The correct choice is that velocity includes direction, while speed does not. Speed is a scalar quantity, measuring how fast something moves, whereas velocity is a vector quantity that specifies both speed and direction.

Benjamin walks from his house to the park and then to the store. Displacement is:

• Always equal to distance

• A vector measurement of how far out of place an object is

• The average speed of an object

• The total distance traveled

Answer explanation

Displacement is defined as a vector measurement that indicates how far out of place an object is, considering both distance and direction. Thus, the correct choice is that displacement is a vector measurement of how far out of place an object is.

Avery walks 3 km east to visit a park and then 4 km west to return home. What is Avery's displacement?

• 1 km east

• 1 km west

• 7 km

• 0 km

Answer explanation

Avery walks 3 km east and then 4 km west. The total distance west is 1 km more than east, resulting in a net displacement of 1 km west from the starting point.

Nora is riding her bicycle down a hill. Which of the following statements is true regarding her acceleration?

• Acceleration can only be positive.

• Acceleration is always uniform.

• Acceleration can be negative (deceleration).

• Acceleration is defined only when an object is moving at constant speed.

Answer explanation

Nora's acceleration can be negative (deceleration) as she rides down the hill. This means she can slow down or change direction, making this statement true. The other options are incorrect regarding the nature of acceleration.

Luna is driving her car. Which of the following describes a situation with negative acceleration?

• A car speeding up

• A car coming to a stop

• A car moving at a constant speed

• A car turning around a corner

Answer explanation

Negative acceleration, or deceleration, occurs when a car is coming to a stop. This means the car's speed is decreasing, which is the opposite of speeding up or maintaining a constant speed.