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3 years ago

Plzzz HELP MEEEE.

Physics

1 answer:

galina1969 [7]3 years ago

7 0

Answer:

D. The state of motion of an object with mass

Explanation:

Specifically, momentum is mv, mass times velocity

You might be interested in

If an object has a mass of 38 kg, what is its approximate weight on earth?

klasskru [66]

38*10=380 N
To be more exact, 38 should be multiplied by 9.8 instead of 10.

3 0

3 years ago

PAY ATTENTION MY QUESTION ASK FOR RADIATION!!!

Anestetic [448]

Answer:

The answer is c

Thermal energy moves within the air from the flames to the marshmallow.

Explanation:

Hope it helps

3 0

3 years ago

When a metal rod is heated, its resistance changes both because of a change in resistivity and because of a change in the length

monitta

Answer:

$3.34\Omega$

Explanation:

The resistance of a metal rod is given by

$R=\frac{\rho L}{A}$

where

$\rho$ is the resistivity

L is the length of the rod

A is the cross-sectional area

The resistivity changes with the temperature as:

$\rho(T)=\rho_0 (1+\alpha (T-T_0))$

where in this case:

$\rho_0$ is the resistivity of silver at $T_0=21.0^{\circ}C$

$\alpha=6.1\cdot 10^{-3} ^{\circ}C^{-1}$ is the temperature coefficient for silver

$T=180.0^{\circ}C$ is the current temperature

Substituting,

$\rho(180^{\circ}C)=\rho_0 (1+6.1\cdot 10^{-3}(180-21))=1.970\rho_0$

The length of the rod changes as

$L(T)=L_0 (1+\alpha_L(T-T_0))$

where:

$L_0$ is the initial length at $21.0^{\circ}C$

$\alpha_L = 18\cdot 10^{-6} ^{\circ}C^{-1}$ is the coefficient of linear expansion

Substituting,

$L(180^{\circ}C)=L_0(1+18\cdot 10^{-6}(180-21))=1.00286L_0$

The cross-sectional area of the rod changes as

$A(T)=A_0(1+2\alpha_L(T-T_0))$

So, substituting,

$A(180^{\circ}C)=A_0(1+2\cdot 18\cdot 10^{-6}(180-21))=1.00572A_0$

Therefore, if the initial resistance at 21.0°C is

$R_0 = \frac{\rho_0 L_0}{A_0}=1.70\Omega$

Then the resistance at 180.0°C is:

$R(180^{\circ}C)=\frac{\rho(180)L(180)}{A(180)}=\frac{(1.970\rho_0)(1.00285L_0)}{1.00572A_0}=1.9644\frac{\rho_0 L_0}{A_0}=1.9644 R_0=\\=(1.9644)(1.70\Omega)=3.34\Omega$

7 0

3 years ago

HELP I DON'T PAY ATTENTION ENOUGH

Setler [38]

Answer:

I think 1 is d and 2 is A

Explanation:

but I may be wrong and I am so sorry if I am

8 0

3 years ago

Read 2 more answers

Researchers recorded the forces over a short period of time (0.065 s) for three different airbag designs as well as one crash wi

kotegsom [21]

Answer:

Design 2

Explanation:

I had this same question

My answer:

"Design 2 is the well-designed one, because the air molecules are the most compact and could protect the individual better than 1,3,and no air bag."

6 0

4 years ago