In general, the quantity of heat energy, Q, required to raise a mass m kg of a substance with a specific heat capacity of c J/(kg °C), from temperature t1 °C to t2 °C is given by:

Q = mc(t2 – t1) joules

So:

(t2-t1) =Q / mc

As we know:
Q = 500 J

m = 0.4 kg

c = 4180 J/Kg °c

We can take t1 to be 0°c

t2 - 0 = 500 / ( 0.4 * 4180 )

t2 - 0 = 0.30°c

6 0

3 years ago

How much speed is needed for an object to travel 250 km in 1.5 hrs? * Your answer

NemiM [27]

Answer: 166.67km/hr

Explanation:

Given the following :

Distance traveled = 250km

Time taken = 1.5 hours

Recall :

Speed = Distance traveled / time taken

Speed = 250 km / 1.5 hours

Speed = 166. 67 km/hr

Speed in m/s:

166.67km/hr = (166.67 × 1000)m / 3600 s

= 166670m / 3600s

= 46.3m/s

7 0

4 years ago

The volume of an ideal gas is adiabatically reduced from 151 L to 80.6 L. The initial pressure and temperature are 1.50 atm and

Zolol [24]

Answer:

gas is dioatomic

T_f = 330.0 K

$\eta = 7.07 mole$

Explanation:

Part 1

below equation is used to determine the type Gas by determining $\gamma$ value

$\frac{V_{1}}{V_{F}}\gamma=\frac{P_{i}}{P_{f}}$

where V_i and V_f is initial and final volume respectively

and P_i and P_f are initial and final pressure

$\gamma = \frac{ln(P_f/P_i)}{ln(V_i/V_f)}$

$\gamma = \frac{ln(3.61/1.50)}{ln(151/80.6}$

\gamma = 1.38

therefore gas is dioatomic

Part 2

final temperature in adiabatic process is given as

$T_f = T_i*[\frac{v_i}{V_f}](^\gamma-1)$

substituing value to get final temperature

$T_f = 260*[\frac{151}{80.6}]^ {(1.38-1)}$

T_f = 330.0 K

Part 3

determine number of moles by using following formula

$\eta =\frac{PV}{RT}$

$\eta =\frac{1.013*10^{5}*0.151}{8.314*260}$

$\eta = 7.07 mole$

4 0

3 years ago

Calculate earth's mass given the acceleration due to gravity at the north pole is 9.830 m/s2 and the mean radius of the earth at

valentinak56 [21]

Answer: $M = 5.98\times 10^{24} kg$

Explanation:

We know that force acting on an object due to Earth's gravity on the surface is given by:

$mg = G\frac{Mm}{r^2}\\ \Rightarrow g = \frac{GM}{r^2}$

where g is the acceleration due to gravity, r would be radius of Earth, M is the mass of Earth and G is the gravitational constant.

It is given that at pole, g = 9.830 m/s² and r = 6371 km = 6371 × 10³ m

$\Rightarrow M = \frac{g\times r^2}{G}$

$M = \frac{9.830 m/s^2 \times (6371 \times 10^3 m )^2}{6.67 \times 10^{-11} m^3 kg^{-1} s^{-2}}$

$\Rightarrow M = 5.98\times 10^{24} kg$

Hence, Earth's mass is $5.98\times 10^{24} kg$

5 0

4 years ago