Directed Reading A worksheet on momentum, mass, and velocity for science education.

Let's solve each question on this Directed Reading A: Momentum worksheet and provide clear explanations.

---

1. Why does it take a large truck longer to stop than a compact car, even though both are traveling at the same velocity?

Answer:
A large truck has more mass than a compact car. Since momentum is the product of mass and velocity, the truck has greater momentum when moving at the same speed as the car. To stop the vehicle, a force must be applied to reduce its momentum to zero. Because the truck has more momentum, it requires more time or a greater force (or both) to stop. This means it takes longer to bring the truck to a stop.

> Explanation: The greater the momentum, the harder it is to change the motion of an object. So, despite having the same velocity, the truck’s larger mass results in higher momentum, requiring more time to stop.

---

2. The product of the mass and velocity of an object is its _________.

Answer:
Momentum

> Explanation: Momentum is defined as the product of an object’s mass and its velocity. It is a vector quantity, meaning it has both magnitude and direction.

---

3. Why does a fast-moving car have more momentum than a slow-moving car of the same mass?

Answer:
Because momentum depends on both mass and velocity. When two objects have the same mass, the one with the higher velocity will have greater momentum.

> Explanation: Since momentum = mass × velocity, increasing velocity increases momentum proportionally. So, a faster-moving car has more momentum than a slower one with the same mass.

---

4. What is the equation used to calculate momentum?

Answer:
p = m × v

Where:
- p = momentum
- m = mass (in kilograms)
- v = velocity (in meters per second)

> Explanation: This formula shows that momentum is directly proportional to both mass and velocity.

---

Match the correct description with the correct term. Write the letter in the space provided.

| Question | Answer | Explanation |
|--------|--------|-----------|
| 5. the mass of an object in kilograms | a. m | 'm' stands for mass in physics equations. |
| 6. the velocity of an object in meters per second | b. v | 'v' represents velocity. |
| 7. units of momentum | c. kg·m/s | Momentum is measured in kilogram-meters per second (kg·m/s). |
| 8. kilograms multiplied by meters per second | c. kg·m/s | This is the unit definition of momentum. |

So:

- 5. a
- 6. b
- 7. c
- 8. c

> Note: Questions 7 and 8 both match to c, which is correct because "units of momentum" and "kilograms multiplied by meters per second" are equivalent.

---

9. What is the direction of momentum?

Answer:
The direction of momentum is the same as the direction of the object's velocity.

> Explanation: Momentum is a vector quantity, so it has both magnitude and direction. Since velocity is also a vector, the direction of momentum follows the direction of motion.

---

✔ Final Answers Summary:

1. It takes longer to stop a large truck because it has more momentum due to its greater mass, requiring more force or time to bring it to rest.

2. Momentum

3. Because momentum depends on velocity; a higher velocity means greater momentum when mass is constant.

4. p = m × v

5. a
6. b
7. c
8. c
9. The direction of momentum is the same as the direction of the object's velocity.

---

This worksheet reinforces the concept of momentum as a key idea in physics related to motion and forces. Understanding how mass and velocity affect momentum helps explain real-world situations like stopping vehicles.