What causes the lens of the camera to extend or retract

You toss a racquetball directly upward and then catch it at the same height you released it 1.82 s later. assume air resistance

Anton [14]

Neglecting air resistance, the acceleration of the ball is
the acceleration of gravity ... 9.8 m/s² downward.

It doesn't matter what you toss, what it's mass is, what it weighs,
what color it is, how much it cost, what its shape or size is, how
fast you toss it, in what direction, or how long it's in the air.

Its horizontal acceleration is zero and its vertical acceleration
is 9.8 m/s² downward, from the moment it leaves your hand
until the moment somebody catches it or it hits the ground.

5 0

3 years ago

Physics help please

zhuklara [117]

Answer: 37.981 m/s

Explanation:

This situation is related to projectile motion or parabolic motion, in which the travel of the ball has two components: x-component and y-component. Being their main equations as follows:

x-component:

$x=V_{o}cos\theta t$ (1)

Where:

$x=52 m$ is the point where the ball strikes ground horizontally

$V_{o}$ is the ball's initial speed

$\theta=0$ because we are told the ball is thrown horizontally

$t$ is the time since the ball is thrown until it hits the ground

y-component:

$y=y_{o}+V_{o}sin\theta t+\frac{gt^{2}}{2}$ (2)

Where:

$y_{o}=120m$ is the initial height of the ball

$y=0$ is the final height of the ball (when it finally hits the ground)

$g=-9.8m/s^{2}$ is the acceleration due gravity

Knowing this, let's start by finding $t$ from (2):

$0=y_{o}+V_{o}sin(0\°) t+\frac{gt^{2}}{2}$ (3)

$0=y_{o}+\frac{gt^{2}}{2}$

$t=\sqrt{\frac{-2 y_{o}}{g}}$ (4)

$t=\sqrt{\frac{-2 (120 m)}{-9.8m/s^{2}}}$ (5)

$t=4.948 s$ (6)

Then, we have to substitute (6) in (1):

$x=V_{o}cos(0\°) t$ (7)

And find $V_{o}$ :

$V_{o}=\frac{x}{t}$ (8)

$V_{o}=\frac{52 m}{4.948 s}$ (9)

$V_{o}=10.509 m/s$ (10)

On the other hand, since we are dealing with constant acceleration (due gravity) we can use the following equation to find the value of the ball's final velocity $V$ :

$V=V_{o} + gt$ (11)

$V=10.509 m/s + (-9.8 m/s^{2})(4.948 s)$ (12)

$V=-37.981 m/s$ (13) This is the ball's final velocity, and the negative sign indicates its direction is downwards.

However, we were asked to find the ball's final speed, which is the module of the ball's final vleocity vector. This module is always positive, hence the speed of the ball just before it strikes the ground is 37.981 m/s (positive).

5 0

2 years ago

What can you infer about the changes in the environment over time at the mystery fossil dig site? Record your inferences in the

vivado [14]

the fossil informed us about the climatic and geographical changes that occurs in the environment over time.

<h3>What the mystery fossil dig site informed us about environment?</h3>

We can infer about the climate and geographical changes in the environment over time at the mystery fossil dig site because the fossil provides us information about the climatic condition as well as the geography of land when this fossil organism were alive.

So we can conclude that the fossil informed us about the climatic and geographical changes that occurs in the environment over time.

Learn more about fossil here: brainly.com/question/11829803

#SPJ1

4 0

1 year ago

These types of electromagnetic waves are listed in order of increasing frequency:

xenn [34]

Answer:

B. X-rays

Explanation:

From the given choices, x-rays will have the highest energy of the given waves.

The energy of electromagnetic waves is highly dependent on their frequency and wavelength.

Electromagnetic waves with a high frequency and small wavelength will have higher energy compared to those with low frequency and high wavelength.

X-rays are one the most energetic waves on the periodic table. They have a very high frequency and low wavelength.

7 0

2 years ago

Read 2 more answers

Harrison wanted to find out what soil works best for growing roses. He grew them in potting soil, clay, sand, and soil he found

zepelin [54]

Answer:

This question is asking to identify the following variables:

Independent variable (IV): TYPE OF SOIL

Dependent variable (DV): HEIGHT AND NUMBER OF LEAVES

Control group: None in this experiment

Constant: SAME ROSE PLANT, SAME TIME INTERVAL (1 WEEK)

Explanation:

Independent variable in an experiment is the variable that is manipulated or changed by the experimenter in order to effect a measurable outcome. In this case, the independent variable is the TYPE OF SOIL used.

Dependent variable is the measurable variable that responds to changes made to the independent variable. In this experiment, the dependent variable is the HEIGHT AND NUMBER OF LEAVES of each rose.

Constants or control variable is the variable that is kept unchanged or constant for all groups throughout the experiment. In this experiment, the constants are SAME ROSE PLANT, SAME TIME INTERVAL (1 WEEK).

Control group are the groups that does not receive the experimental treatment. In this case, all the groups received the experimental treatment (different soil types). Hence, there is no control

4 0

3 years ago