Physics 12 December Practice Quiz

 

1)      Sketch the “Map of the Physical Universe” and outline how it relates to the basic forces of nature.

2)      Convert to MKS units: 

a)      13 mg

b)      2.11 cs

c)       16.4 g/mm³

3)      Give the following in decimal form:

a)      3.2 × 10³

b)      5.13 × 10^-5          

4)      Give the following in scientific notation:

a)      46000

b)      0.0008065

5)      Consider the following vectors:  A is force of 35 N directed at 15º below the negative x-axis and B is a force of 24 N directed at 70º below the positive x-axis.

a)      Sketch A and B.

b)      Sketch the graphical sum of the two vectors.

c)      Use components to find B – A.  

6)      A runner runs from Laguna Alalay to the Mormon Temple which is 3.5 km to the north in 10 minutes.

a)      What is their displacement?

b)      What is their average velocity?

c)      If they are traveling at 2.0m/s  3.0 seconds before they arrive at the Temple and come to a stop at the end of their run, what is their average acceleration for the last 3.0 seconds?

7)      A ball is thrown with an purely upward velocity of 2.5 m/s from a height of 50.0 m:

a)      How high will the ball go?

b)      How long will it take to hit the ground?

c)      With what velocity will it hit the ground? 

8)      A ball is thrown with an initial velocity of 20 m/s at an angle of 25º above the horizontal:

a)      How long until it reaches a height of 1.0 m?

b)      How far will it have traveled horizontally at this point?

c)      What will its velocity be at this point?

9)      State any two of Newton's Laws in your own words and explain them using examples.

10)  Consider a block of mass equal to your mass lying on a horizontal surface with a string attached to it pulling upwards with a force of 10N (μ_k=0.500 and μ_s=0.800 between the block and the surface). 

a)      Another rope is used to pull on the block with a force of magnitude 100N directed to the right.  Draw the free body diagram for the block showing all the forces and labeling them according to their type (normal, tension, weight, static friction, etc.) and value.

b)      Describe the reaction force for each of the forces.  (Think Newton’s Third Law.)

c)      What is the maximum force that can be applied by the horizontal rope without the block moving?

d)      What will happen if the horizontal rope applies a force twice the magnitude of what you found in answer c)? (Be explicit. )

11)  Two blocks are lying on top of each other on a smooth (frictionless) horizontal surface.  The top block has a mass equal to the day of your birth (if you were born August 21^st, use a mass of 21 kg).  The block on the bottom has a mass of 40kg. The bottom block has a rightward horizontal force of 20N being applied to it.   There is a force of friction between the two blocks but you do not know the coefficients.  The blocks move together; there is no sliding between the two blocks.

a)      Draw a free body diagram for each block, and write out the equations for them.

b)      With what acceleration will the blocks travel?

c)      What is the minimum possible coefficient of static friction?

d)      What is the total force of interaction between the two blocks? (There are two kinds.)

12)  A block of your mass is sliding down a ramp inclined 35˚ to the horizontal.

a)      Draw the free body diagram for the block, choose and show a coordinate frame and draw an arrow representing the acceleration down the ramp labeled a.

b)      Write out the equations in the x and in the y directions from the diagram and using N2.

c)      Solve the equations to find:

i)        The normal force on the block.

ii)      The acceleration of the block.

13)  Describe how you can use a simple pendulum to measure the acceleration due to gravity.  (The equation of importance is:  P = 2π√(L/g), where L is the length of the pendulum and P is its period.  Assume you have graph paper, a ruler, a stopwatch, some known masses and string.)