Describe a device that transforms thermal energy into another useful form. tes that

A ductile metal wire has resistance R. What will be the resistance of this wire in terms of R if it is stretched to three times

Ira Lisetskai [31]

Answer:

9R

Explanation:

We know that the resistance is $R=\rho *\frac{L}{A}$ .

If we stretch the wire to a new length L2 = 3L, the cross-sectional area will also change. If the cross-sectional area doesn't change throughout the wire, we can say that:

Volume = L*A = 3L * A2 being A2 the new area after stretching the wire.

Since the volume remains the same we conclude that A2 = A/3

With this information, we calculate the new resistance:

$R2=\rho *\frac{L2}{A2}=\rho *\frac{3*L}{A/3}=\rho * 9 * \frac{L}{A}$

Since $R=\rho *\frac{L}{A}$ , and by simple inspection of the previous equation, we get:

R2 = 9*R

6 0

3 years ago

The driver of a car traveling at a speed of 27 m/s slams on the brakes and comes to a stop in 3 s. If we assume that the speed c

NISA [10]

Answer:

Average speed = 13.5 m/s

Explanation:

Since the car is running at a speed of 27 m/s and it stops after 3 seconds by applying the brake. Therefore, the initial speed of the 27 m/s and final speed is 0.

Use below formula to find the average speed :

Average speed = (Initial speed + final speed ) / 2

Average speed = (27 + 0 ) / 2

Average speed = 13.5 m/s

7 0

3 years ago

The illustration represents one form of _________________, the process that enables all stars, including our sun, to continuousl

jonny [76]

We have no way to say what the illustration represents, mainly because
you haven't given us a way to see the illustration.

However, the process that all stars, including our sun, use to continuously
produce energy is nuclear fusion.

8 0

4 years ago

Read 2 more answers

Unpolarized light passes through three polarizing filters. The first one is oriented with a horizontal transmission axis, the se

Xelga [282]

Answer:

10.028%

Explanation:

$\theta$ = Angle between polarizer