PHYS 1405 Sample Questions (1-4)
Write each formula before using. Show your work, and box your answer and its correct units.
Short answer questions in complete sentences without adding unnecessary or incorrect
information. Points are in brackets []. Allowed Materials: Calculator, 3”x5” note-card.
Useful Information: g = 10. m/s/s
[2] What was the main error in Aristotle’s reasoning regarding the motion of an object with
constant velocity? Contrast this incorrect idea with Newton’s 1st Law.
[3] A 100 N plank supports two painters as shown. One painter has a weight of 800 N and the
other 500 N. The tension in one of the support ropes is 1000 N. Calculate the tension in the
other rope. Show your starting equation and work. Box your answer and units.
A 10kg object has a 20 N force pulling on it to the right and a 10 N force pulling on it to the
left. No other forces act.
a) [1] Draw a force diagram for the object.
b) [1] Calculate the net force acting on the object.
c) [2] Write down Newton’s 2nd Law and use it to calculate the acceleration of the object in
m/s/s units. Box your answer.
Calculate the velocity of a freely falling object 2.0 seconds after being released from rest.
Show your formula, work, and box answer and unit for credit.
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Draw a force diagram which represents an object falling with air friction force that is one-half
the weight of the object. Label each force in your diagram with a word or phrase description
(do not use symbols).
As done in class, add the vectors in the force diagram shown below. Is the NetForce zero or
non-zero? _____________ If the NetForce is not zero, draw the arrow representing its size and
direction and label it “NetForce”.
A car accelerates uniformly from rest to 20m/s with constant acceleration of 4m/s/s.
Calculate the elapsed time for this event.
Multiple Choice [1 point each]. Circle the best answer only.
1. What is the net force on a 2kg object that is in free-fall?
0 newtons
5 newtons
10 newtons
20 newtons
none of the these
2. What is the net force on a 2kg object sitting at rest on your desk?
0 newtons
5 newtons
10 newtons
20 newtons none of the these
3. Which of the following is not a vector quantity?
velocity
mass
acceleration
all are vector quantities.
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