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Name ________________________________________Mods ________________________

STUDY GUIDE

UNIT 9-Newton’s Second Law: F=ma

Mon, Dec 14 Lab-

Dependence of Acceleration on Force

Complete graph

Tues, Dec 15 Go Over Graph and Lab ● finish lab report

● Read Section 5.1-5.3

and take notes in packet

● Watch Video and take

notes

Wed, Dec 16 Sample F=ma problem

Problem Set A

● Problem Set B

● Read Section 5.4-5.5

and take notes in packet

Thurs, Dec 17 Lab-Coefficient of Friction Watch Video and take notes

Fri, Dec 18 Problem Set C Study for test

Mon, Dec 21 Review for test Study for test

Tues, Dec 22 Test - Newton’s Second Law-F=ma

Wed, Dec 23 ½ day

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CP Physics

Reading Notes

Section 5.1-5.3

1. Write the equation for acceleration:

acceleration = __________

2. This chapter focuses on the _______________ of acceleration: _______________

3. To increase the _______________ of an object, you must _______________ the net

force acting on it

a. accelection is ______________ ______________ to net force

4. Acceleration depends on the _______________ being pushed

a. the same force applied to _______________ as much mass results in only

________________ the acceleration

b. for _______________ times the mass, _______________ the acceleration

results

c. For a given force, the acceleration produced is _______________

________________ to the mass

5. What is the equation for acceleration in terms of mass and force

acceleration = ____________________

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CP PHYSICS

PROBLEM SET A

F = ma EQUATIONS

F = m a Fg = m g

Key:

F = force (in N)

m = mass (in kg)

a = acceleration (in m/s2)

Fg = weight (in N)

g = acceleration due to gravity (10 m/s2)

1. What force is needed to accelerate a 2000 kg car at 15 m/s2?

2. A bowler imparts an acceleration of 40 m/s2 to a normal bowling ball during his release. Assuming the force

he gives the ball is 292 N, what is the mass of the ball in kg?

3. A pick-up truck has a mass of 1800 kg. If its engine is producing a force of 7200 N, what will the truck's

acceleration be?

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4. How much does a 0.25 kg wrench weigh on earth?

5. On one of Saturn's moons (Titan) the acceleration due to gravity is about 5 m/s2. How much would an astronaut

on Titan weigh if his mass is 85 kg?

6. On the planet Nebula, a 7 kg object weighs 35 N. What is the acceleration due to gravity on Nebula?

7. On Mars, g is equal to 6.4 m/s2 and an astronaut weighs 358.4 N. What is the mass of the astronaut?

ANSWERS: Not in Order (Some answers may be used more than once)

0.56 2.5 4 5 7.3 56 225 425 30,000 56,000

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PHYSICS

PROBLEM SET B

F=ma EQUATIONS

1. A 0.75 kg book is pushed across the table with an acceleration of 0.3 m/s2. What force is being applied to the

book?

2. During take off, a small 460 kg plane can undergo an acceleration of 6 m/s2. How much force the propeller is

supplying?

3. A 1500 kg sports car can accelerate at a rate of 5.2m/s2. What force does its engine give the car during this

acceleration?

4. On the launch pad, the Space Shuttle has a mass of 2,000,000 kg. In order to lift off, its engines must produce a

combined thrust of 29,250,000 N. What is the initial acceleration of the Space Shuttle?

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5. What is the weight of a 150 kg object (on Earth)?

6. What is the mass of a box that weighs 450 N?

7. What is the acceleration due to gravity on a planet where a 15 kg rock weighs 925 N?

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CP Physics

Reading Notes

Section 5.4-5.5

1. Friction is a _____________ like any other force and affects _______________

2. Friction acts on materials that are in ______________ with each other, and always acts

in the direction to _____________ motion

3. The force of friction between the surfaces depends on the _______________ in contact

and _______________ the surfaces are pressed together

4. _______________, which is the friction acting on something moving through

__________, is a very common form of fluid friction

5. The amount of _______________ per unit _____________ is called _______________

6. The equation for pressure is:

pressure = ____________________

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CP PHYSICS

PROBLEM SET C

FRICTION PROBLEMS

1.) What is the force of friction acting on a 453 N sled if the m between the sled and the floor is

0.23?

2.) What is the force of friction acting on a 67 kg box if the m between the box and the floor is

0.06?

3.) What is the acceleration of a 720 kg car that is being pushed by a truck with a force of

7,000N if the m between the tires and the road is 0.87?

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COEFFICIENT OF KINETIC FRICTION

Define Friction:

What factors affect friction?

What is the equation used to calculate friction?

Use algebra to solve for the coefficient of friction from the equation above:

Record the mass of one book = _______________ kg

Calculate the weight of one book:

Number of Books Normal Force (N) -

Weight

Kinetic Friction (N) – for

book sliding on table)

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2

3

4

5

6

7

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Describe the relationship between normal force (weight) and kinetic friction:

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Graph friction force vs normal force (weight). Calculate the slope of the best fit line.

What does this value represent?