PHYA11H3 Lecture Notes - Lecture 3: One Direction

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rosewater-buffalo535

27 Sep 2018

School

UTSC

Department

Physics and Astrophysics

Course

PHYA11H3

Professor

Gyula Lorincz

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PHYA11H3 Lecture 2: Introduction to Physics_ Lecture 2

PHYA11H3 Lecture Notes - Lecture 3: One Direction

PHYA11H3 Lecture 4: [PHYA11][Lec 04]-[Integrals, Motion with Constant Acceleration, and Kinematics’ Equations]

Document Summary

The motion of an object is described by three important and fundamental qualities: it displacement (position), velocity and acceleration. Since we are using these quantities in one dimension, we must give them explicit signs- indicating whether the position, velocity or acceleration() is moving forward (+) or backwards (-). When dealing with acceleration, one must be careful because one assumes that a positive value for means that it is speeding up and that a negative value of means that is slowing down. Acceleration in one direction is defined as. The direction of must be determined using a motion diagram and analysing what the direction of the velocity is and whether the object is speeding up or slowing down. Constant velocity is when: the sign of an object"s acceleration indicated which way the acceleration vector is pointing, not whether its slowing down down or speeding up.

Related Questions

A particle moves according to a law of motion s = f(t), t ≥ 0, where t is measured in seconds and s in feet.

(a) Find the velocity at time t.

(b) What is the velocity after 1 second?

(d) When is the particle moving in a positive direction?

(e) Find the total distance travelled during the first 6 seconds.

(f) Draw a diagram like a Figure 2 to illustrate the motion of the particle.

(g) Find the acceleration at time t and after 1 second.

(h) Graph the position, velocity, and acceleration functions for 0 ≤ t ≤ 6.

(i) When is the particle speeding up? When is it slowing down?

FIGURE 2

f(t) = t³ – 8t² + 24t

beigewhale140

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

1. Which of the following describes an object with a non-zero netforce acting on it? Choose all that apply.
The moped accelerated while making a left turn.
The motorcycle traveled at a constant speed while making au-turn.
The truck slowed down while making a right turn.
The spaceship traveled at a constant speed in a straightline.
The car sped up from 50 mph to 65 mph while moving in a straightline.

2. If you observe that an object is accelerating, what should youconclude?
A non-zero net force is acting on it. Only forces causeacceleration. As such, if an object is accelerating it must bebecause a non-zero net force is acting on it.
It must be in free fall.
It must be changing direction. Acceleration is a vector and vectorshave both magnitude and direction. Thus if an object isaccelerating it must be changing direction.
The forces acting on the object must be greater than the forces theobject is exerting.
It must be speeding up. If an object is accelerating that means itis speeding up.

3. Which of the following are true according to Newton's 2nd Law?Choose all that apply.

If the acceleration is zero, then the net force is zero.
If you apply the same force to 2 objects, the one with more masswill have a greater acceleration.
If you apply the same force to 2 objects, the one with less masswill have a greater acceleration.
If two objects have the same acceleration, the one with less masswill have a larger net force exerted on it.
If two objects have the same acceleration, the one with more masswill have a larger net force exerted on it.
The larger the net force on an object is, the larger theacceleration.
The larger the net force on an object is, the smaller theacceleration.

4. A box is on the Moon. The box weighs 152 lb and is in free fall.How much force is the box exerting on the Moon and in whatdirection?

lb
Up
Down
Right
North
East
West
Left
South

5. Which of the following are the correct units for mass? Chooseall that apply.
slugs
u
kgÂ·m/s2
g
N
m/s2
oz
lb

6. If an object is traveling in a circle, which of the followingmust be TRUE? Choose all that apply.
The object is slowing down.
The object is speeding up.
The object has a net force acting on it.
The object has a constant velocity.
The object is accelerating.

PHYA11H3 Lecture Notes - Lecture 3: One Direction

PHYA11H3 Lecture 2: Introduction to Physics_ Lecture 2

PHYA11H3 Lecture Notes - Lecture 3: One Direction

PHYA11H3 Lecture 4: [PHYA11][Lec 04]-[Integrals, Motion with Constant Acceleration, and Kinematics’ Equations]

Document Summary

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Physics: Principles with Applications

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