Geo-physical science- projectile motion

Projectile

any object that moves the air or through space under the influence of gravity

Example of a curved path of projectile (parabola)

a stone thrown horizontally curves downward due to gravity

Projectile curves are a result of what two components?

• constant motion horizontally

• accelerated motion vertically

Projectile motion is a combination of a _______ component and a ________ component.

horizontal, vertical

In a parabola, only the ________velocity component changes with time. The _________ component remains constant.

vertical, horizontal

The velocity of a typical projectile can be represented by horizontal and vertical components. Assuming negligible air resistance, the horizontal component along the path of the projectile…

remains the same

When no air resistance acts on a fast-moving baseball, its acceleration is…

downward, g

Projectile altitude and range- for equal launching speeds, the same range is obtained from two different projection angles — a pair that add up to ___.

90°

Example: Same range occurs for a 75° launch and a ___ launch of the same initial.

15°

A ball tossed at an angle of 30° with the horizontal will go as far downrange as one tossed at the same speed at an angle of

60°

With air resistance, both range and altitude on projectiles are ______

decreased

Without air resistance, the speed lost on projectiles going up is __________ as the speed gained while coming down

the same

Comparison of change of position, velocity, and acceleration

(see picture)

Example of predicting position as a function of time

emergency plane landing

Equation for free fall (?)

Equals 9.8 m/s². It is only under the influence of gravity.

In our lab experiment, then the motion sensor was pointing downward, what did the plotted computer data show?

displacement, velocity, and acceleration

Projectile motion

Motion under the influence of gravity near Earth’s surface has essentially constant acceleration whose magnitude is g=9.8m/s², and whose direction is downward.

Horizontal and vertical motions are _______

independent

Equations for projectile motion, in a coordinate system with y axis vertically upward.

(see picture)

___ is like our falling projectile. But we have a ___ world (like going from a photograph in 2-D to a sculpture in 3-D)

2-D, 3-D

Vectors

show direction and magnitude (or quantity)

We can add, subtract, or multiply _______

vectors

Any change in velocity is an __________ (again, NOT just speeding up)

acceleration

A car driving around a corner … even at the same _____ … is acceleration.

speed

What is circular motion?

One of the most important types of motion in the universe. Acceleration motion. Uniform circular motion is accelerated, even if the same speed, because it is changing direction.

Circular motion is…

accelerated motion

Examples of circular motion

• Car wheel turning. Both wheel and car turning, therefore two accelerations.

• Airplane turning

• Hands on a clock

• Earth orbiting the sun

• Bicycle wheels turning (and pedals)

Equation for circular motion

a = ∆v / ∆t