Test 1 Review

Physics I Sp 01

 

Here is a sampling of problems that I would expect you to be able to solve, or answer.

 

1) Given 1 km = .62 miles, convert miles/hour to meters/min.

 

2) When measuring a rectangle for a class project lazy Goofus only measures to the nearest cm and measures 4 x 5 for an area of 20 sq. cm.  Gallant takes his time

and measures to the nearest mm, getting 3.6 x 4.7, and he report the area as 16.9 sq cm.

Which area measurement is more accurate, and why?  Who had points deducted for

having the wrong number of significant figures in his answer, and why?

 

3) If you read that a star is an order of magnitude of 5 larger than the earth, how many times the size of earth is the star?

 

4) Given A = 3i – 2j + 2k, and B = 2i + j - 2k Find:

 

a) 2A + B

 

b)

 

c)

 

d)

 

e) The angle between A and B

 

5) A man walks 4 miles at 42 degrees N of E, then walks 7 miles 50 degrees W of N.  What is the magnitude and direction of his net displacement?

 

6) Describe the difference between translational motion and rotational motion. Why can

an object undergoing translational motion be treated as a “point” object?

 

7) A car travels west for 50 miles at a speed of 70 miles/ hour, then immediately returns

at 60 miles per hour.  Find the total distance traveled and displacement of the car.  Find

the average speed, and average velocity of the car.

 

8) The position of a particle is given by the equation

 

a)Find the average velocity between t = 1, and t = 3.

 

b) Find the instantaneous velocity at t = .5

 

c) Find the instantaneous acceleration at t = 1

 

d) Find the average acceleration between t = 1, and t = 2.

 

 

9) Consider the velocity (m/s) vs. time (s) graph.

 

 

 


v

 

10

 

5

 

   0               5            10             15                

 

 

a) Where is the acceleration positive, zero, negative?

 

b) Does the particle ever reverse direction?  If so, at what time?

 

c) Estimate the displacement of the particle between 5 and 10 seconds.

 

d) Estimate the average velocity between 0 and 5 seconds.

 

e) Estimate the average acceleration between 0 and 5 seconds. 

 

10) A car is initially moving at 112 km/h.  Find its acceleration and the time

taken to stop given that:

 

a) it brakes to a stop in 64m

 

 b) it crashes into a wall and crumples in 1 m.