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1 year ago

What makes up the atomic mass of an element?

Physics

1 answer:

UNO [17]1 year ago

8 0

Answer: The sum of protons and neutrons in the nucleus

Explanation: The Formula For Atomic Mass or Mass Number is

Atomic mass= Protons + Neutrons

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Newton's law of cooling is , where is the temperature of an object, is in hours, is a constant ambient temperature, and is a pos

kirill [66]

Complete Question

The complete question is shown on the first uploaded image

Answer:

The time taken is $t = 6.89 \ hrs$

Explanation:

From the question we are told that

The value of $k = 0.15hr^{-1}$

The the interior temperature is $u(t = 0) = 70 ^oF$

The external temperature is $T = 11 ^oF$

The required interior temperature is $u_{t} = 32 ^oF$

The newton cooling law is

$\frac{du}{dt} = -k (u -T)$

=> $\frac{du}{u-T} = - kdt$

Now integrate both sides we have

$\int\limits \frac{du}{u-T} =\int\limits - kdt$

$ln (u - T) = -kt + c$

Since c is a constant lnC = c will also give a constant so

$ln (u - T) = -kt + ln C$

=> $\frac{(u -T)}{C} = e^{-kt}$

=> $u = T + Ce^{-kt}$

substituting value

$70 = 11 +Ce^{-0* 0.15}$

$C = 59$

Hence

$u_t = 11 + 59 e^{-0.15 *t}$

$32= 11 + 59 e^{-0.15 *t}$

=> $t = -\frac{ln(\frac{21}{59} )}{0.15}$

$t = 6.89 \ hrs$

3 0

2 years ago

11. A dog sits 2.50m from the center of a merry-go-round and revolves at a tangential

pshichka [43]

Fc=mv2/r formula of centripetal force will be applied here with radius mass and velocity described in the above question

5 0

2 years ago

Does red or green light have more energy.

dalvyx [7]

Answer: Green Light

Explanation:

The color green has a higher frequency than the color red and the higher the frequency the more energy. If you looks at a rainbow you'll see red on one end and violet on the other. Red has the least energy Violet has the most.

7 0

1 year 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

A car travels straight for 20 miles on a road that is 30Â° north of east. What is the east component of the carâ€™s displacement

Over [174]

The east component of the cars displacement is 17.3 miles.

Trigonometric ratio is used to show the relationship between the sides of a right angled triangle and its angles.

Let x represent the east component of the cars displacement.

Using trigonometric ratio:

cos(30) = x / 20

x = 20 * cos(30)

x = 17.3 miles

The east component of the cars displacement is 17.3 miles.

Find out more on Trigonometric ratio at: brainly.com/question/1201366

4 0

1 year ago