Question

physics final exam study guide

1. a car accelerates at a constant rate of 3.0 m/s². if the car has a mass of 750 kg, how much net force is on the car?
2. a 5 kg vacuum cleaner is being pushed along a floor with a horizontal force of 40 n. what is the acceleration of the vacuum?
3. a refrigerator is being pushed along a floor with a force of 240 n. the fridge accelerates at a rate of 4.80 m/s². what is the mass of the fridge?
4. what is the definition of momentum?
5. what are the units of momentum?
6. find the momentum of the following objects:

a. a 12 kg shopping cart rolling along at 2 m/s
b. a 2,250 kg truck driving at 10 m/s
c. a 250 kg scooter driving at 8 m/s

Explanation:

Question 6

Step1: Recall Newton's second law

Newton's second law is \( F = ma \), where \( F \) is force, \( m \) is mass, and \( a \) is acceleration.

Step2: Substitute values

Given \( a = 3.0 \, \text{m/s}^2 \) and \( m = 750 \, \text{kg} \), substitute into the formula: \( F = 750 \times 3.0 \)

Step3: Calculate the force

\( F = 2250 \, \text{N} \)

Step1: Recall Newton's second law

Newton's second law is \( F = ma \), rearranged to \( a = \frac{F}{m} \) for acceleration.

Step2: Substitute values

Given \( F = 40 \, \text{N} \) and \( m = 5 \, \text{kg} \), substitute into the formula: \( a = \frac{40}{5} \)

Step3: Calculate the acceleration

\( a = 8 \, \text{m/s}^2 \)

Step1: Recall Newton's second law

Newton's second law is \( F = ma \), rearranged to \( m = \frac{F}{a} \) for mass.

Step2: Substitute values

Given \( F = 240 \, \text{N} \) and \( a = 4.80 \, \text{m/s}^2 \), substitute into the formula: \( m = \frac{240}{4.80} \)

Step3: Calculate the mass

\( m = 50 \, \text{kg} \)

Answer:

The net force on the car is \( 2250 \, \text{N} \)

Question 7