PH-UY 1013 Lecture Notes - Lecture 1: Dynamic Equilibrium, Statics, Net Force

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limehamster162

7 Sep 2016

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Document Summary

Displacement vectors are basis for velocity and acceleration vector quantities. They all together describe motion of an object in space. Speed- scalar quantity and is equal to magnitude of velocity vector. Uniform velocity occurs when speed and direction of moving object are constant. Slope is equal to magnitude of object"s velocity. Uniform acceleration in d vs. t graph is a parabola. Slope of a lone tangent to d-t graphs is equal to instantaneous velocity. Acceleration- vector quantity and is time-rate of change of velocity. Equation: acceleration (a)= change in velocity(vf-vi)/change in time (tf-ti) Uniform acceleration is when an object"s velocity is changing by a fixed amount per second. A- uniform acceleration; b- no acceleration; c- gradual acceleration; d- object is decelerating or slowing uniformly. Deceleration- slowing down or going in opposite direction. Area under v-t graph represents the distance object has traveled. Statics the study of the effect of forces on stationary objects.

Related Questions

I. v = +2.0 m/s, Δt = 2.0 s

II. v = +3.0 m/s, Δt = 2.0 s

III. v = -3.0 m/s, Δt = 2.0 s

Which option ranks the displacement of there objects in decreasing order?

a. I, II, III

b. II, III, I

c. II, I, III

d. III, II, I

11. Which of these defines acceleration? Choose the correct answer.

a. the change in velocity

b. the change in displacement

c. change of velocity over time

d. the rate of change of displacement

12. An object moves at a constant speed in the direction of the arrow.

Which of these describes the object's movement? Choose the correct answer.

a. positive velocity

b. negative velocity

c. positive acceleration

d. negative acceleration

mariabran12

1. What is the difference between speed and velocity?

a. Speed is an average quantity while velocity is not.

b. Velocity contains information about the direction of motion while speed does not.

c. Speed is measured in mph, while velocity is measure in m/s.

d. The concept of speed applies only to objects that are neither. speeding up or slowing down, while velocity applies to every kind of motion.

e. Speed is used to measure how fast an object is moving in a straight line, while velocity is used for objects moving along curved paths.

2. The quantity 2.67 x 10³ has how many significant figures?

3. If Libby walks 100 m to the right, then 200 m to the left, her net displacement vector points

a. to the right.

b. to the left.

c. has zero length.

d. cannot tell without more information.

4. Velocity vectors point

a. in the same direction as displacement vectors.

b. in the opposite direction as displacement vectors.

c. perpendicular to displacement vectors.

d. in the same direction as acceleration vectors.

e. velocity is not represented by a vector.

chocolatemouse942

A small object with a mass of 4.00 kg moves counterclockwise with a constant angular speed of 1.50 rad/s in a circle of radius 3.00 m centered at the origin.

a) It started at the point with cartesian coordinates (3m, 0). When its angular displacement is 9.00 rad, what is its position vector, int cartesian unit vector notation?

b) In what quadrant is the particle located, and what angle does its position vector make with the positive x-axis?

c) What is its velocity vector, in-unit vector notation?

d) In what direction is it moving? Make a sketch of the position and velocity vectors

e) What is its acceleration, expressed in unit-vector notation?

f) What total force acts on the object? (Express your answer in unit vector notation)