Newton S 2Nd Law: Problems (And Quiz Review)

Newton’s 2nd Law: Problems (and Quiz Review)

Equations - Speed/Velocity, Acceleration and Force

Regular: You will be given the equations and their forms.

Honors: You will be given the equation, but not all of their forms.

Material

Regular and Honors: you are responsible for all of the material in 2.1 and 2.2.

Prior material may be part of the quiz. (example: conversions)

-What is Force? How is Net Force different?

-What unit is used for force? What is the definition of that unit?

-What is Inertia? How does inertia relate to Newton’s first law?

-Newton’s second law.

-How does mass relate to both Newton’s first and second laws?

-How are mass and weight different?

Other hints: Make sure of your units.

List your known(s) and unknowns

Did you read/outline that big collection of colorful pages called the text?

Some Practice Problems (equation based)

Answers for the problems are available on the web site.

1. Mr. McIntyre is chasing his neighbor’s dog (Snaggle-tooth) down the block. He covers 100 meters in 14 seconds. What is Mr. McIntyre’s velocity in m/sec? How about cm/s?
2. Mr. McIntyre is gaining ground on the Snaggle-tooth. He is 20 meters closer after 10 seconds. If both the Snaggle-tooth and Mr. McIntyre are running at constant speed, what is the velocity of the Snaggle-tooth? (in m/sec)
3. Mr. McIntyre notices the reason for the fleeing mongrel. Snaggle-tooth was chasing a Grosse Pointe Bushy Tailed Rat (aka. A squirrel). The chased squirrel started at a velocity of 1 m/sec and increased to a velocity of 4.7 m/sec in 1.2 sec. What is the acceleration of the GP Bushy Tailed Rat?
4. Mr. McIntyre the 76 kg Snaggle-tooth by the collar. He stops Snaggle-tooth in 2 seconds from the dog’s original velocity to a stop. What is the amount of force (in Newtons) required to do this?
5. The G.P. bushy tailed rat is now taunting Snaggle-tooth at a safe distance. Mr. McIntyre throws a Burrito Supreme (which he had in his pocket) at the G.P. bushy tailed rat in order to scare it away. What would the acceleration be of the Burrito be if he used 75 N of force on the 1.1 kg burrito? (it is the acceleration while throwing)

6. Order the following mass measurements from smallest to largest:

0.5 kilograms, 1,000 grams, 5 kilograms, 50 grams.

7. Dani and Gina are pushing on a box. Dani pushes with 250 N of forceand Gina pushes with 100 N of force.

a. What is the net force if they both push in the same direction?

b. What is the net force if they push in opposite directions?

8. You start from rest and ski down a hill with an acceleration of2 m/sec2. Find your speed at the following times:

a. 1 second

c. 3 seconds

d. 10 seconds

Answers Below

1. 7.14 m/s 714 cm/sec.
2. 5.14 m/sec.
3. 3.1 m/sec.2
4. 195.32 N
5. 68.2 m/sec.2
6. 50 g, .5 kg, 1000g, 5kg
7. A. 350N B. 150N
8. A. 2m/sec2, B. 6m/sec.2 C. 20m/sec.2

What do you want to know? What do you know? The formula you will use