Ask question

Ask question

All categories

3 years ago

7

To calibrate your calorimeter cup, you first put 45 mL of cold water in the cup, and measure its temperature to be 24.7 °C. You

then pour 47 mL of hot water, temperature = 46.1 °C, into the cup and measure the temperature every thirty seconds over a 10 minute period. You extrapolate this "cooling curve" back to the time of addition and find that the "final temperature" after mixing is 33.4 °C. What is the heat change of the cold water in Joules? Give your answer in standard notation. Do not input units.

1 answer:

drek231 [11]3 years ago

4 0

Answer : The heat change of the cold water in Joules is, $1.6\times 10^3J$

Explanation :

First we have to calculate the mass of cold water.

As we know that the density of water is 1 g/mL. The volume of cold water is 45 mL.

$Density=\frac{Mass}{Volume}$

$Mass=Density\times Volume=1g/mL\times 45mL=45g$

Now we have to calculate the heat change of cold water.

Formula used :

$Q=m\times c\times (T_2-T_1)$

where,

Q = heat change of cold water = ?

m = mass of cold water = 45 g

c = specific heat of water = $4.184J/g^oC$

$T_1$ = initial temperature of cold water = $24.7^oC$

$T_2$ = final temperature = $33.4^oC$

Now put all the given value in the above formula, we get:

$Q=45g\times 4.184J/g^oC\times (33.4-24.7)^oC$

$Q=1638.036J=1.6\times 10^3J$

Therefore, the heat change of cold water is $1.6\times 10^3J$

You might be interested in

On earth, two parts of a space probe weigh 14500 N and 4800 N. These parts are separated by a center-to-center distance of 18 m

Nastasia [14]

Answer:

$F = 1.489*10^{-7} N$

Explanation: Weight of space probes on earth is given by: $W= m*g$

W= weight of the object( in N)

m= mass of the object (in kg)

g=acceleration due to gravity(9.81 $\frac{m}{s^{2} }$ )

Therefore,

$m_{1} = \frac{14500}{9.81}$

$m_{1} = 1478.08 kg$

Similarly,

$m_{2} = \frac{4800}{9.81}$

$m_{2} = 489.29 kg$

Now, considering these two parts as uniform spherical objects

Also, according to Superposition principle, gravitational net force experienced by an object is sum of all individual forces on the object.

Force between these two objects is given by:

$F = \frac{Gm_{1} m_{2}}{R^{2} }$

G= gravitational constant ( $6.67 * 10^{-11} m^{3} kg^{-1} s^{-2}$ )

$m_{1} , m_{2}$ = masses of the object

R= distance between their centres (in m)(18 m)

Substituiting all these values into the above formula

$F = 1.489*10^{-7} N$

This is the magnitude of force experienced by each part in the direction towards the other part, i.e the gravitational force is attractive in nature.

7 0

3 years ago

Adam drops a ball from rest from the top floor of a building at the same time Bob throws a ball horizontally from the same locat

guapka [62]

Answer:

Both balls hit the ground at the same time

Explanation:

Adam drops the ball from rest, so the ball just "<em>falls</em>" in vertical direction, being gravity its only acceleration, for cinematic movements we use that:

$y(t)=y_{0}+v_{0y}t+\frac{1}{2}gt^{2}$

In this case we have that gravity is negative, and as Adam drops the ball, $v_{0y}=0$

Bob throws the ball horizontally, so the movement will be a <em>parabola</em>, we can divide into horizontal direction, and vertical direction.

But we only need to analize the vertical movement, in wich again the only acceleration is gravity, and compare it with Adam's ball. Again we have that gravity is negative, and as the initial throw is horizontal, $v_{0y}=0$

Finally, we have that

$y(t)=h-\frac{1}{2}gt^{2}$

where

$h=y_{0}$

both for Adam's vertical drop, and for Bob's vertical component of the parabolic throw.

Now, if we put $y(t)=0$ (the origin of the vertical coordinate), we get for both cases that

$h=\frac{1}{2}gt^{2}$

where we can clear the value for the time t, of the fall, wich will be the same in both cases.

Hence, both balls hit the ground at the same time.

3 0

3 years ago

Lake point tower in chicago is the tallest apartment building in the united states. suppose you take the elevator from street le

notka56 [123]

Using the idea of work done under gravity, the height of the building is 187 m.

<h3>Work done in a gravitational field</h3>

We must recall that the work done in a gravitational field is given by; mgh

m= mass

g = acceleration due to gravity

h = height

mass = 60.0 kg

Workdone = 1.15x10^5 J

W = mgh

h = W/mg

h = 1.15x10^5 J/60.0 kg * 9.8 ms-2

h = 187 m

Learn more about work done: brainly.com/question/13662169?

7 0

2 years ago

A nearsighted person cannot see objects further away than 10 m clearly. This person wants to be able to see objects 300 m away w

icang [17]

Answer:

d.-10.3m

Explanation:

Note for short sightedness the focal length is negative

Let do be object distance=10m

And di= image distance=-300m

Using lens formula

F=do*di/do-di= 10*300/10-300=-10.3m

4 0

3 years ago

Read 2 more answers

Movement of a specific direction is called

aleksklad [387]

Velocity. Velocity is physical vector quantity; both magnitude and direction are needed to define it. Magnitude is this case meaning speed.

8 0

3 years ago