What happens once a scientific theory is accepted

The track of a roller coaster is shown below. At which point will the riders experience centripetal acceleration?

valentinak56 [21]

Centripetal acceleration is applied in circular motion. Y is the point on the track that most closely resembles a circular path for the roller coaster.

4 0

2 years ago

Read 2 more answers

Which is not a physical property?

mihalych1998 [28]

The correct answer to the question is D). Ability to combine with oxygen.

EXPLANATION:

Before going to answer this question, first we have to understand physical and chemical change.

The change or reaction is said to be physical if there will be no change in the chemical configuration of the substance. The property corresponding to this change is called physical property which won't change the configuration of the substance. It is measurable and simply denotes the physical states of a system.

A chemical change is a change in which a new substance is formed due to the chemical reaction. Here, both the reactants and products have different chemical configuration. The property corresponding to it is called chemical property.

As per our questions, hardness, boiling and ability to conduct electricity are the physical properties of a substance.

The ability to combine with oxygen is not a physical property. It is so because it will result into the formation of a new compound.

Hence, the correct answer to the question is the ability to combine with oxygen.

3 0

3 years ago

A pilot flies in a straight path for 1 h 30 min. She then makes a course correction, heading 10 degrees to the right of her orig

atroni [7]

Answer:

The plane is 2353.7 mi from the starting position.

Explanation:

Please, see the attached figure for a graphic representation of the problem.

We have 2 displacement vectors "a" and "b" and a vector "c" that is the sum of vectors "a" plus "b" (c = a + b). The module of "c" will be the distance of the plane from the starting point.

vector a = (xa, ya)

vector b = (xb, yb)

where “xa” and “xb” are the horizontal components of the vectors “a” and “b” respectively and “ya” and “yb” are the vertical components of each vector.

Then, the vector c = a + b will be:

c = (xa + xb, ya + yb)

The module of a vector is calculated using the following expression for a vector “v”:

module of v = $\sqrt{x^{2} + y^{2} }$

Then, the module of c will be:

module of c = $\sqrt{(xa + xb)^{2} + (ya + yb)^{2}}$ = distance from starting point

Then, we have to find the components of vectors “a” and “b”

The distance traveled during the first 1.5 hours of the trip is the module of the vector “a”. Then:

module of a = $\sqrt{xa^{2} + ya^{2} }$ = distance traveled during the first 1.5 hours.

The distance can be calculated using the equation of the position of an object moving in a straight line at constant speed:

x = x0 + v * t

where

x = position at time t

x0 = initial position

v = speed

t = time

Considering x0 as the starting point (x0 = 0)

x = 675 mi/h * 1.5 h = 1012.5 mi

Then:

module of a = $\sqrt{xa^{2} + ya^{2} }$ = 1012. 5 mi

Since the plane moves only on the horizontal (see figure), the "y" component of the vector, "ya", will be 0.

Then:

(1012.5 mi)² = xa²

xa = 1012. 5mi

a = (1012.5 mi, 0)

In the same way, we have fo find the components of the vector “b”. The module of “b” will be the distance traveled during this part of the flight:

module of b = $\sqrt{xb^{2} + yb^{2} }$ = x = x0 + v * t

Considering x0 as the point at which the plane turns (x0 = 0)

x = 675 mi / h * 2 h = 1350 mi

Using trigonometry, we can calculate xb and yb (see figure):

sin angle = opposite / hypotenuse

cos angle = adjacent / hypotenuse

In this case:

opposite = yb

adjacent = xb

hypotenuse = module of “b”

Then:

sin 10° = yb / module of “b”

sin 10° * module of “b” = yb

In the same way:

cos 10° * module of “b” = xb

Since module of “b” = 1350 mi

xb = 1329.5 mi

yb = 234.4 mi

b = (1329.5 mi, 234.4 mi)

The vector c = a+b can now be calculated:

c = (xa + xb, ya + yb)

c =(1012.5 mi + 1329.5 mi, 0 mi + 234.4 mi) = (2342 mi, 234.4 mi)

The module of c will be:

module of c = $\sqrt{(2342 mi)^{2} + (234.4 mi)^{2} }$ = 2353.7 mi

The plane is 2353.7 mi from the starting position.

4 0

3 years ago

A sprinter accelerates from rest to 10.0 m/s in 1.28 s . Part A Part complete What is her acceleration in m/s2? a a = 7.81 m/s2

Mashutka [201]

Explanation:

It is given that,

Initial speed of sprinter, u = 0

Final speed of sprinter, v = 10 m/s

Time taken, t = 1.28 s

a. We need to find the acceleration of sprinter. It can be calculated using first equation of motion as :

$a=\dfrac{v-u}{t}$

$a=\dfrac{10\ m/s}{1.28\ s}$

$a=7.81\ m/s^2$

b. Final speed of the sprinter, v = 36 km/h

Time, t = 0.000355 h

Acceleration, $a=\dfrac{36}{0.000355}$

$a=101408.45\ km/h^2$

Hence, this is the required solution.

3 0

3 years ago

Who did not have experimental evidence to support his theory of the atom? Dalton Thomson Rutherford Democritus

Aloiza [94]

Democritus was the one who did not have experimental evidence to support his theory of the atom.

Answer: Option 4

<u>Explanation: </u>

The discovery of atoms were first stated by Democritus but due to the absence of any experimental proof, his statement was not noted as significant at that time.

After this, Dalton made the specific assumptions formulating some postulates for the atomic theory with proof. Then the cathode rays tube experiments performed by Thomson lead to the formation of plum pudding models of atom.

This is followed by Rutherford’s gold foil experiment discovering the presence of nucleus inside the atoms. So, Democritus first stated but due to absence of experimental evidences, his theory of atoms were not supported at that time.

3 0

3 years ago