![Picture](/uploads/4/7/6/6/47660241/1426997866.png)
Key Terms:
1D equations:
(equations can only be used when there is constant acceleration)
Key Facts:
Multiple Choice Questions:
#1. A baseball pitcher delivers a fast ball. During the throw, the speed of the ball increases from 0 to 30.0 m/s over a time of 0.100 seconds. The average acceleration of the baseball is ____ m/s^2.
a. 3.00
b. 30.0
c. 300
d. 3000
e. none of these
#2. A car travels 90. meters due north in 15 seconds. Then the car turns around and travels 40. meters due south in 5.0 seconds. What is the magnitude of the average velocity of the car during this 20.-second interval?
a. 2.5 m/s
b. 5.0 m/s
c. 6.5 m/s
d. 7.0 m/s
e. 15 m/s
#3. A ball is thrown vertically up and is caught when it returns to the same vertical position from which it was thrown. The ball takes 3 seconds to reach its maximum height. For what total time interval is the ball in the air? Neglect air friction.
a. between 3 seconds and 6 seconds
b. 6 seconds
c. longer than 6 seconds
d. 9.8 seconds
e. 19.6 seconds
#4. An object is released from rest and falls in the absence of air resistance. Which of the following is true about its motion?
a. Its acceleration is zero
b. Its acceleration is constant
c. Its velocity is constant
d. Its acceleration is increasing
e. Its velocity is decreasing
#5. To throw a ball as far as possible, you should throw it at which angle:
a. 30 o
b. 60 o
c. 45 o
d. 90 o
e. the angle doesn’t matter – it only depends on the velocity
Open-ended Questions:
#1. A baseball is thrown 42m/s horizontally from a height of 2 meters. How far will the ball travel before it reaches the ground?
#2. A race car accelerates uniformly from 18.5 m/s to 46.1 m/s in 2.47 seconds. Determine the acceleration of the car and the distance traveled.
#3. A projectile is launched straight up at 60 m/s from a height of 80m, at the edge of a cliff. The projectile falls just missing the cliff and hits the ground below.
a. Find the max height the projectile reached above the firing point
b. Find the time it takes the projectile to reach the ground
c. Find the projectiles velocity at impact
Helpful Videos:
https://www.youtube.com/watch?v=D9wQVIEdKh8
This video relates to the unit because it shows how a bullet fired from a specific distance will hit the ground at the same time as a bullet dropped straight down
https://www.youtube.com/watch?v=wQupPFO0P8M
This video gives good background information on how to organize the kinematics problems by setting up tables and analyzing the data given
- Scalar: a quantity fully described by its magnitude (numerical value)
- Vector: a quantity fully described by a magnitude and a direction
- Distance: the quantity that represents the length of a given path
- Displacement: vector quantity that starts at the beginning of the motion and finishes at the end
- Frame of Reference: a coordinate system used to represent the motion
- Projectile: any object in which only the force of gravity is acting upon it
1D equations:
(equations can only be used when there is constant acceleration)
Key Facts:
- For a projectile, the acceleration in the x direction is always zero
- If one object is dropped from the same height that a similar object is launched from a projectile, both objects will hit the ground at the same time
- Fg is always -9.8 m/s in a projectile motion problem
- The y and x components of a projectile motion problem are independent of each other, besides time
- Initial velocity of x is equal to the final velocity of x (velocity on the x never changes)
- 1D kinematics can be used when the object is moving either left and right or up and down
- 2D kinematics can be used for projectile motion (both left or right and up or down at the same time)
- With projectile motion, the x and y axes are linked by time (t)
- When working with objects thrown at an angle, first thing to do is split into the x and y axis
Multiple Choice Questions:
#1. A baseball pitcher delivers a fast ball. During the throw, the speed of the ball increases from 0 to 30.0 m/s over a time of 0.100 seconds. The average acceleration of the baseball is ____ m/s^2.
a. 3.00
b. 30.0
c. 300
d. 3000
e. none of these
#2. A car travels 90. meters due north in 15 seconds. Then the car turns around and travels 40. meters due south in 5.0 seconds. What is the magnitude of the average velocity of the car during this 20.-second interval?
a. 2.5 m/s
b. 5.0 m/s
c. 6.5 m/s
d. 7.0 m/s
e. 15 m/s
#3. A ball is thrown vertically up and is caught when it returns to the same vertical position from which it was thrown. The ball takes 3 seconds to reach its maximum height. For what total time interval is the ball in the air? Neglect air friction.
a. between 3 seconds and 6 seconds
b. 6 seconds
c. longer than 6 seconds
d. 9.8 seconds
e. 19.6 seconds
#4. An object is released from rest and falls in the absence of air resistance. Which of the following is true about its motion?
a. Its acceleration is zero
b. Its acceleration is constant
c. Its velocity is constant
d. Its acceleration is increasing
e. Its velocity is decreasing
#5. To throw a ball as far as possible, you should throw it at which angle:
a. 30 o
b. 60 o
c. 45 o
d. 90 o
e. the angle doesn’t matter – it only depends on the velocity
Open-ended Questions:
#1. A baseball is thrown 42m/s horizontally from a height of 2 meters. How far will the ball travel before it reaches the ground?
#2. A race car accelerates uniformly from 18.5 m/s to 46.1 m/s in 2.47 seconds. Determine the acceleration of the car and the distance traveled.
#3. A projectile is launched straight up at 60 m/s from a height of 80m, at the edge of a cliff. The projectile falls just missing the cliff and hits the ground below.
a. Find the max height the projectile reached above the firing point
b. Find the time it takes the projectile to reach the ground
c. Find the projectiles velocity at impact
Helpful Videos:
https://www.youtube.com/watch?v=D9wQVIEdKh8
This video relates to the unit because it shows how a bullet fired from a specific distance will hit the ground at the same time as a bullet dropped straight down
https://www.youtube.com/watch?v=wQupPFO0P8M
This video gives good background information on how to organize the kinematics problems by setting up tables and analyzing the data given