Projectiles+Study+Questions

__**Projectiles Study Questions**__

Post any original questions that you develop from your summaries of this chapter. Read what your classmates have posted and be sure NOT to duplicate them.

> 1. The object will have a parabolic trajectory in the downward direction. > 1. Vector diagrams may be drawn at the points on which a projectile falls, and their magnitudes represent the velocity. > Non-horizontal launch is when an object is launched upward and at an angle to the horizontal. > They are generally similar concepts, yet projectile motion has 2 components, while free fall by itself only concerns one. > 4.What is the point of using tables to find the motion of projectiles? > 5. Why do the displacement equations look familiar? > The object would continue at the same speed in the same direction > > 30. What does gravity do to the projectile? > Gravity causes a vertical acceleration. Gravity is the downward force on a projectile which influences the vertical motion and causes the parabolic motion. > > > 31. What is a symmetrical projectile? > Magnitude of the velocity is the same at equal intervals of time on either side of its peak.
 * 1) What is a projectile?
 * 2) It is an object dropped from rest or thrown vertically upwards at an angle to the horizontal
 * 3) It is any object projected or dropped that continues in motion by its own inertia
 * 4) What is inertia?
 * 5) The resistance an object has to a change in a state of motion
 * 6) Can projectiles move in a direction other than vertical motion?
 * 7) Yes, projectiles can move in a horizontal motion as well. Horizontal and vertical are both COMPONENTS of the projectile.
 * 8) Does gravity affect the horizontal motion of a projectile?
 * 9) No, it does not. This is because gravity acts as a downward force, therefore unable to affect the horizontal motion
 * 10) Is the velocity of downward vertical motion changing or constant?
 * 11) It is ALWAYS changing, due to the account of gravity's acceleration of -9.8 m/s/s.
 * 12) What is the velocity of horizontal trajectory? vertical?
 * 13) Constant and changing, respectively.
 * 14) What are the equations for certain projectiles?
 * 15) <span style="font-family: 'Trebuchet MS',Helvetica,sans-serif;">vertical displacement for a 1D object
 * 16) <span style="font-family: 'Trebuchet MS',Helvetica,sans-serif;">y= 1/2gt <span style="font-family: 'Trebuchet MS',Helvetica,sans-serif; vertical-align: super;">2
 * 17) <span style="font-family: 'Trebuchet MS',Helvetica,sans-serif;">vertical displacement for a horizontally launched projectile
 * 18) <span style="font-family: 'Trebuchet MS',Helvetica,sans-serif;">X= V <span style="font-family: 'Trebuchet MS',Helvetica,sans-serif; vertical-align: sub;">ix <span style="font-family: 'Trebuchet MS',Helvetica,sans-serif;">t
 * 19) <span style="font-family: 'Trebuchet MS',Helvetica,sans-serif;">vertical displacement for an angled-launched projectile
 * 20) <span style="font-family: 'Trebuchet MS',Helvetica,sans-serif;">v <span style="font-family: 'Trebuchet MS',Helvetica,sans-serif; vertical-align: sub;">iy <span style="font-family: 'Trebuchet MS',Helvetica,sans-serif;">t+ 1/2gt <span style="font-family: 'Trebuchet MS',Helvetica,sans-serif; vertical-align: super;">2
 * 21) <span style="font-family: 'Trebuchet MS',Helvetica,sans-serif;">Can vertical motion increase? decrease?
 * 22) <span style="font-family: 'Trebuchet MS',Helvetica,sans-serif;">Yes, the diagram should most of the time look like a parabola (parabolic trajectory). Therefore, the velocities will increase and decrease.
 * 23) What type of trajectory does an object have when shot horizontally?
 * 1) How are vector diagrams used to express the motion of a projectile?
 * 1) What are the different kinds of projectiles?
 * 2) [[image:Free-Bods.png width="224" height="113"]]
 * 3) How is a free-body diagram represented?
 * 4) [[image:Free-Bods2.png width="74" height="94"]]
 * 5) If an object is thrown into the air, then why is momentum not an acting force?
 * 6) According to Newton’s laws, forces are only required to initial motion and horizontal acceleration, but not to keep an object in motion. After the object is released, it is acted upon by gravity only, and is a projectile.
 * 7) How is horizontal motion explained?
 * 8) According to Newton’s first law of motion, a projectile in motion (such as horizontal motion) will stay in motion unless acted upon by an unbalanced force. Gravity does not affect a projectile’s horizontal motion.
 * 9) Why do projectiles travel in a parabolic shape?
 * 10) The downward force of gravity accelerates projectiles downward from their gravity-free trajectories, causing an increasing curve towards the ground.
 * 11) If gravity does not act upon a horizontal projectile, then what force does act on it?
 * 12) Gravity acts downward on a projectile and cannot change its horizontal motion; therefore, a horizontal force causes horizontal acceleration. There is also vertical force acting upon projectiles. A projectile is acted upon by constant horizontal velocity and downward vertical acceleration.
 * 13) What is the displacement of a projectile trajectory?
 * 14) The downward force and acceleration of a projectile result in a downward displacement from the gravity-free position.
 * 15) Does the vertical force affect the horizontal force?
 * 16) No, because the two forces are perpendicular; therefore, the vertical force is independent of the horizontal force.
 * 17) **<span style="font-family: 'Times New Roman',Times,serif;">What is the difference between horizontal and non-horizontal projectile launch? **
 * 1) **<span style="font-family: 'Times New Roman',Times,serif;">How is projectile motion different from free fall? **
 * 1) Does a projectile ever have the same speed at two points in time?
 * 2) Yes. The projectile's speed is symmetrical about the peak of its position. If an object is thrown at 45 degree angle, its speed at 2 seconds before the peak is the same as it is 2 seconds after the peak.
 * 3) How does the displacement of a horizontally launched projectile change over time?
 * 4) The horizontal displacement changes by the same amount every second, but the vertical displacement changes by a larger amount every second.
 * 5) Is the vertical velocity ever zero?
 * Yes, at the peak of the path, the y velocity is zero
 * 1) What is different about horizontal velocity, as opposed to vertical velocity?
 * Horizontal velocity has constant speed and has no force acting upon that. Gravity affects the vertical motion, and pulls any object downwards. Vertical motion does not have constant speed.
 * 1) How does inertia affect projectile?
 * Inertia is the resistant of change. A force needs to be acted upon an object so that the inertia does not affect the object and change is allowed. When an object is projecting, the inertia does not affect the object, or else it would travel in a constant line forever and ever. Gravity affects the motion of the object and therefore diminishes the inertia?
 * 1) What happens when a projectile is launched from an angle?
 * The same thing as when it is dropped or thrown straight up. It follows a parabolic trajectory always; it just depends what point on the parabola you start on.
 * 1) What do Newton's laws have to do with projectiles?
 * 2) Newton's law of inertia explains that projectiles will move and change when the force of gravity acts upon the object. Many have a misconception that an object going up is being acted upon by an upward force. This is not true and this is explained by Newton.
 * 3) How do you numerically calculate the motion of projectiles?
 * 4) You can use two equations to find the horizontal and vertical components.
 * 5) How do you find the path if launched from an angle?
 * 6) You can find it the same way, except it will have an initial horizontal and vertical velocity that do not equal 0.
 * 1) Using a table helps to pinpoint the path of the projectile object in number sense. You can get a visual representation after, but the table helps to numerically understand what is going on with the projectile. Testing time points are also useful.
 * 1) These equations are derived from 2-D kinematics equations, and velocity, time, acceleration, and displacement will also have the same relationships.
 * 2) Why is there a force? A force is only required to maintain an acceleration.
 * 3) 29. What would happen in the absence of gravity?
 * 1) What is the difference between the free body diagrams of projectiles moving dowards, upwards, upwards and rightwards, or downwards and leftward?
 * 2) There is no difference, free body diagrams all look the same regardless of direction. They always look like this: [[image:u3l2a3.gif]].
 * 3) What information must you look for for horizontally launched projectiles?
 * 4) are there any forces? If so, what direction are they? Is there acceleration? If so, is it constant or changing?
 * 5) What would happen to the vertical component of velocity if there was no gravity? The vertical component of velocity would not change, instead of decreasing.
 * 6) What formula shows horizontal displacement of a projectile? Vertical displacement?
 * 7) y=(V i x) x (t)
 * 8) y= (v i y) x (0.5x) x (g) x (t 2 )
 * 9) How many forces act upon projectiles? What if there are more?
 * 10) only one force (gravity) can act upon projectiles; if there is more than one force acting upon the object, it is not considered a projectile
 * 11) What is the horizontal velocity of a projectile?
 * 12) The horizontal velocity of a projectile is ALWAYS constant
 * 13) Are there different types of projectile motion?
 * Yes.
 * 1) Object dropped from rest
 * 2) Object thrown vertically upward
 * 3) Object thrown upward at an angle
 * 1) What are the characteristics of a projectile?
 * A projectile is any object upon which the only force is gravity
 * Projectiles travel with a parabolic trajectory due to the influence of gravity
 * There are no horizontal forces acting upon projectiles and thus no horizontal acceleration
 * The horizontal velocity of a projectile is constant (a never changing in value)
 * There is a vertical acceleration caused by gravity; its value is 9.8 m/s/s, down
 * The vertical velocity of a projectile changes by 9.8 m/s each second
 * The horizontal motion of a projectile is independent of its vertical motion.
 * 1) How are projectiles measured?
 * By how the numerical values of the x- and y-components of the velocity and displacement change with time (or remain constant).
 * By how the numerical values of the x- and y-components of the velocity and displacement change with time (or remain constant).