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4 years ago

I need to know the answer to the question

Physics

1 answer:

galben [10]4 years ago

4 0

I would go with A. An Observation. Because he's looking at visual differences, for example: "based on smell, color change, and release of bubbles.

You might be interested in

How many atoms are in a sample of 1.83 moles of potassium (K) atoms?

telo118 [61]

Avogadro's number represents the number of units in one mole of any substance. This has the value of 6.022 x 10^23 units / mole. This number can be used to convert the number of atoms or molecules into number of moles.

1.83 moles K (6.022 x 10^23 atoms / mole ) = 1.10 x 10^24 atoms K

4 0

3 years ago

The height (in meters) of a projectile shot vertically upward from a point 3 m above ground level with an initial velocity of 21

frutty [35]

Answer:

a) The velocity of the projectile at 2 seconds after launch is 1.9 meters per second. The velocity of the projectile at 4 seconds after launch is -17.7 meters per second.

b) The projectile reaches maximum height 2.192 seconds after launch.

c) The maximum height of the projectile is 26.584 meters above ground.

d) The projectile will hit the ground at 4.523 seconds after launch.

e) The velocity of the projectile right before hitting the ground in -22.871 meters per second.

Explanation:

Complete statement of problem is: The height (in meters) of a projectile shot vertically upward from a point 3 m above ground level with an initial velocity of 21.5 meters per second is $h(t) = 3+21.5\cdot t-4.9\cdot t^{2}$ after t seconds. (Round your answers to two decimal places.) (a) Find the velocity after 2 seconds and after 4 seconds, (b) When does the projectile reach its maximum height? (c) What is the maximum height? (d) When does it hit the ground? (e) With what velocity does it hits the ground?

a) From Physics and Differential Calculus we remember that velocity is the first derivative of height. Hence, we need to differentiate the height function in time:

$v(t) = 21.5-9.8\cdot t$ (Eq. 1)

Where $v(t)$ is the velocity function, measured in meters per second.

Now we evaluate this function at given times:

t = 2 s.

$v(2) = 21.5-9.8\cdot (2)$

$v(2) = 1.9\,\frac{m}{s}$

The velocity of the projectile at 2 seconds after launch is 1.9 meters per second.

t = 4 s.

$v(4) = 21.5-9.8\cdot (4)$

$v(4) = -17.7\,\frac{m}{s}$

The velocity of the projectile at 4 seconds after launch is -17.7 meters per second.

b) Maximum height is reached when velocity of projectile is zero. We equalize velocity to zero and solve the expression for $t$ :

$21.5-9.81\cdot t = 0$

$t = 2.192\,s$

The projectile reaches maximum height 2.192 seconds after launch.

c) Maximum height is calculated by evaluating height function at the time found in b). That is:

$h(2.192) = 3+21.5\cdot (2.192)-4.9\cdot (2.192)^{2}$

$h (2.192) = 26.584\,m$

The maximum height of the projectile is 26.584 meters above ground.

d) In this case, we need to equalize the height function to zero and solve for $t$ . That is:

$3+21.5\cdot t-4.9\cdot t^{2} = 0$

Roots are found by means of Quadratic Formula:

$t_{1}\approx 4.523\,s$ and $t_{2}\approx -0.135\,s$

Only the first root offers a physically reasonable solution. Therefore, the projectile will hit the ground at 4.523 seconds after launch.

e) This can be found by evaluating velocity function at the time found in d):

$v(4.523) = 21.5-9.81\cdot (4.523)$

$v(4.523) = -22.871\,\frac{m}{s}$

The velocity of the projectile right before hitting the ground in -22.871 meters per second.

5 0

4 years ago

Compare the gravitational force the sun exerts on Earth to the gravitational force Earth exerts on the sun.

podryga [215]

Answer:

Mass of sun > Mass of earth

Therefore, the sun will exert more gravitational force on earth.

Explanation:

While comparing the gravitational force exerted by two objects, we need to observe which object has a greater mass.

The object with the greater mass exerts a more gravitational force on the other object.

We know that mass of the sun is about 1.99 x 10³⁰ kg, and the earth's mass is only 6.0 x 10²⁴.

Mass of sun > Mass of earth

Therefore, the sun will exert more gravitational force on earth.

7 0

3 years ago

A dog is walking back home and its motion is modeled by the graph above. What position was the dog at 3 seconds after it started

hammer [34]

6 meters because 6/3 = 10/5

4 0

3 years ago

g the newly launched satellite has a gyroscope inside of it. the gyroscope has a moment of inertia that is 1/10 of that of the r

Ivenika [448]

Answer:

Explanation:

For every action, there is an equal and opposite reaction.

As the moment of inertia if the gyroscope is 1/10 of that of the remainder of the satellite, the angular velocity of the satellite will be 1/10 that of the spun up gyroscope and in the opposite direction.

L = Iω

4 0

3 years ago