If 25.0 g of water at 21c is mixed with 45.0 g of water at 75c, what is the final temperature of the mixture?

Five race cars speed toward the finish line at the Jasper County Speedway. The table lists each car’s speed in meters/second. If

nekit [7.7K]

We have: v = d/t
From the expression, we conclude speed is indirectly proportional to speed.
So, the car which will take longer time must have the smallest speed. Among all the options Car C has the smallest speed. So, it would be your answer.

In short, Your Answer would be Option C) Car C will take longer time than any other.

Hope this helps!

6 0

2 years ago

Read 2 more answers

PLEASE HELP ASAP BEST ANSWER WILL BE MARKED BRAINLIEST!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

pantera1 [17]

Answer:

It is the 3 one

Explanation:

3 0

3 years ago

A boy flies a kite with the string at a 30 degree angle to the horizontal. The tension in the string is 4.5N .

sp2606 [1]

How much work in J does the string do on the boy if the boy stands still?

answer: None. The equation for work is W = force x distance. Since the boy isn't moving, the distance is zero. Anything times zero is zero 
--------------------------------------... 
How much work does the string do on the boy if the boy walks a horizontal distance of 11m away from the kite? 

answer: might be a trick question since his direction away from the kite and his velocity weren't noted. Perhaps he just set the string down and walked away 11m from the kite. If he did this, it is the same as the first one...no work was done by the sting on the boy. 

If he did walk backwards with no velocity indicated, and held the string and it stayed at 30 deg the answer would be: 
4.5N + (boys negative acceleration * mass) = total force1 
work = total force1 x 11 meters 
--------------------------------------... 

How much work does the string do on the boy if the boy walks a horizontal distance of 11m toward the kite? 

answer: same as above only reversed: 
4.5N - (boys negative acceleration * mass) = total force2 
work = total force2 x 11 meters

6 0

3 years ago

When you irradiate a metal with light of wavelength 433 nm in an investigation of the photoelectric effect, you discover that a

sergij07 [2.7K]

Answer:

The right solution is:

(a) 2.87 eV

(b) 1.4375 eV

Explanation:

Given:

Wavelength,

= 433 nm

Potential difference,

= 1.43 V

Now,

(a)

The energy of photon will be:

E = $\frac{6.626\times 10^{-34}\times 3\times 10^8}{433\times 10^{-9}}$

= $4.59\times 10^{-19} \ J$

or,

= $\frac{4.59\times 10^{-19}}{1.6\times 10^{-19}}$

= $2.87 \ eV$

(b)

As we know,

⇒ $Vq=\frac{hc}{\lambda}-\Phi_0$

By substituting the values, we get

⇒ $1.43\times 1.6\times 10^{19}=\frac{6.626\times 10^{-34}\times 3\times 10^8}{433\times 10^{-9}}-\Phi_0$

⇒ $\Phi_0=2.3\times 10^{-19} \ J$

or,

⇒ $=\frac{2.3\times 10^{-19}}{1.6\times 10^{-19}}$

⇒ $=1.4375 \ eV$

5 0

3 years ago

A 50-g cube of ice, initially at 0.0°C, is dropped into 200 g of water in an 80-g aluminum container, both initially at 30°C.

MakcuM [25]

Answer:

b. 9.5°C

Explanation:

$m_i$ = Mass of ice = 50 g

$T_i$ = Initial temperature of water and Aluminum = 30°C

$L_f$ = Latent heat of fusion = $3.33\times 10^5\ J/kg^{\circ}C$

$m_w$ = Mass of water = 200 g

$c_w$ = Specific heat of water = 4186 J/kg⋅°C

$m_{Al}$ = Mass of Aluminum = 80 g

$c_{Al}$ = Specific heat of Aluminum = 900 J/kg⋅°C

The equation of the system's heat exchange is given by

$m_i(L_f+c_wT)+m_wc_w(T-T_i)+m_{Al}c_{Al}=0\\\Rightarrow 0.05\times (3.33\times 10^5+4186\times T)+0.2\times 4186(T-30)+0.08\times 900(T-30)=0\\\Rightarrow 1118.5T-10626=0\\\Rightarrow T=\dfrac{10626}{1118.5}\\\Rightarrow T=9.50022\ ^{\circ}C$

The final equilibrium temperature is 9.50022°C

4 0

3 years ago