CK-12 Physical Science Concepts - For Middle School

(Marvins-Underground-K-12) #1

http://www.ck12.org Chapter 4. Motion and Forces


accelerate at 0.8 m/s^2?


A: It would take only 32 N of force (40 kg×0.8 m/s^2 ).


At the URL below, you can review how to calculate net force from mass and acceleration and try some practice
problems. If you want to try more challenging problems, click on the relevant links at the bottom of the Web page.


http://www2.franciscan.edu/academic/mathsci/mathscienceintegation/MathScienceIntegation-856.htm


Summary



  • According to Newton’s second law of motion, the acceleration of an object equals the net force acting on it
    divided by its mass, or a=Fm.

  • This equation for acceleration can be used to calculate the acceleration of an object when its mass and the net
    force acting on it are known.

  • The equation for acceleration can be rewritten as F = m×a to calculate the net force acting on an object when
    its mass and acceleration are known.


Vocabulary



  • acceleration: Measure of the change in velocity of a moving object.


Explore More


At the following URL, solve the six problems on page 2.


http://www2.fcsconline.org/staff/ferrisa/Kinesiology/Force%20WS.pdf


Review



  1. What is the equation for calculating the acceleration of an object when its mass and the net force acting on it
    are known?

  2. Xander’s friend Corey has a skateboard that he rides at Newton’s Skate Park. That’s Corey doing a jump in
    theFigure4.48. The combined mass of Corey and his skateboard is 60 kg. At the top of his jump, the net
    force acting on him is 30 Newtons. What is his acceleration at that moment?

  3. What net force would have to act on Cory for him to have an acceleration of 1 m/s^2?

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