A pondering physics student paces forward and backward. His motion is shown on the following graph of

A house has well-insulated walls. It contains a volume of 105 m3 of air at 305 K.

REY [17]

Answer: $85.46\ kJ$

Explanation:

Given

Volume of air $V=105\ m^3$

Temperature of air $T=305\ K$

Increase in temperature $\Delta T=0.7^{\circ}C$

Specific heat for diatomic gas is $C_p=\dfrac{7R}{2}$

Energy required to increase the temperature is

$\Rightarrow Q=nC_pdT\\\\\Rightarrow Q=n\times \dfrac{7R}{2}\times \Delta T\\\\\Rightarrow Q=\dfrac{7}{2}nR\Delta T\\\\\Rightarrow Q=\dfrac{7}{2}\times \dfrac{PV}{T}\times \Delta T\quad [\text{using PV=nRT}]$

Insert the values

$\Rightarrow Q=\dfrac{7}{2}\times \dfrac{1.01325\times 10^5\times 105}{305}\times 0.7\\ \text{Assuming air pressure to be atmospheric P=}1.01325\times 10^5\ N/m^2\\\\\Rightarrow Q=0.8546\times 10^5\\\Rightarrow Q=85.46\ kJ$

6 0

3 years ago

How do you know when motion has occurred?

Masteriza [31]

An object in motion changes position

7 0

4 years ago

What is the distance covered in 20 minutes by a train traveling 500m/m?

MrMuchimi

Answer:

answer is 10km

Explanation:

use "S =Ut "

S=distance U=velocity t =time

no need to convert time into seconds as the velocity has given in meters per minute

3 0

4 years ago

How does the width of the floodplain change over time?

serg [7]

Floodplains are landscapes shaped by running water. As streams and their larger forms, rivers, flow across the surface of land, they transport eroded rock and other material. (Erosion is the gradual wearing away of Earth surfaces through the action of wind and water.) At points along that journey, when their flow slows, the material they carry is dropped to create what are termed depositional landforms. Among these landforms are deltas and floodplains.

Read more: http://www.scienceclarified.com/landforms/Faults-to-Mountains/Floodplain.html#ixzz7BNHuUb00

8 0

2 years ago

a rugby player passes the ball 5.34 m across the field, where it is caught at the same height as it left his hand. at what angle

MakcuM [25]

Answer:

$31.035^{\circ}$

Explanation:

x = Displacement in x direction = 5.34 m

t = Time taken to travel the displacement

y = Displacement in y direction = 0

u = Initial velocity of ball = 7.7 m/s

g = Acceleration due to gravity = $9.81\ \text{m/s}^2$

Displacement in x direction is given by

$x=u\cos\theta t\\\Rightarrow t=\dfrac{5.34}{7.7 \cos\theta}$

Displacement in y direction is given by

$y=u\sin\theta t-\dfrac{1}{2}gt^2\\\Rightarrow 0=7.7\sin\theta \dfrac{5.34}{7.7\cos\theta}-\dfrac{1}{2}\times 9.81 (\dfrac{5.34}{7.7\cos\theta})^2\\\Rightarrow 0=7.7\sin\theta-4.905\times \dfrac{5.34}{7.7\cos\theta}\\\Rightarrow 0=7.7^2\sin\theta \cos\theta-4.905\times 5.34\\\Rightarrow 0=7.7^2\dfrac{\sin2\theta}{2}-4.905\times 5.34\\\Rightarrow 0=7.7^2\sin2\theta-4.905\times5.34\times 2\\\Rightarrow \sin2\theta=\dfrac{4.905\times 5.34\times 2}{7.7^2}\\\Rightarrow 2\theta=\sin^{-1}\dfrac{4.905\times 5.34\times 2}{7.7^2}$

$\Rightarrow \theta=\dfrac{62.07}{2}\\\Rightarrow \theta=31.035^{\circ}$

The angle at which the ball was thrown is $31.035^{\circ}$ .

7 0

3 years ago