Ask question

Ask question

All categories

pickupchik [31]

3 years ago

11

Which material BEST allows electricity to pass through it?

1 answer:

gavmur [86]3 years ago

3 0

The answer is A) Graphite

You might be interested in

A proton in the nucleus of an atom has an electrical charge of:<br> neutral<br> -<br> +<br> zero

dlinn [17]

Answer:

proton is positively charged changechar

Explanation:

6 0

2 years ago

A horizontal force of 93.7 N is applied to a 42.5 kg crate on a rough, level surface. If the crate accelerates at 1.03 m/s2, wha

vovangra [49]

Answer:

49.925N

Explanation:

According to newton's second law of motion:

$\sum Fx = ma_x$

$\sum Fx$ is the sum of force along the x component

m is the mass of the crate

ax is the acceleration

$Fm - Fk = ma_x$

Fk is the magnitude of the force of kinetic friction

Given

Fm = 93.7

m = 42.5kg

a = 1.03m/s²

Substitute into the formula:

$93.7 - Fk = (42.5)(1.03)\\93.7-Fk = 43.775\\Fk = 93.7 - 43.775\\Fk = 49.925N$

Hence the magnitude of the force of kinetic friction (in N) acting on the crate is 49.925N

8 0

3 years ago

To what temperature must you raise a silver wire (c = 0.0038), originally at 20.0°C, to double its resistance, neglecting any ch

balu736 [363]

Answer:

$T=283^{\circ}C$

Explanation:

Given a material with temperature coefficient of resistance <em>c</em>, the equation that relates the resistance $R_0$ at temperature $T_0$ and the resistance $R$ at temperature $T$ is

$\frac{R-R_0}{R_0}=c(T-T_0)$

We want to double our resistance, so $R=2R_0$ , thus having:

$\frac{2R_0-R_0}{R_0}=\frac{R_0}{R_0}=1=c(T-T_0)$

For this T must be:

$1=cT-cT_0$

$T=\frac{1+cT_0}{c}$

which for our values means (with $T=20^{\circ}C=293^{\circ}K$ , remember to write temperature in S.I., and that for silver $c=0.0038^{\circ}K^{-1}$ ):

$T=\frac{1+(0.0038^{\circ}K^{-1})(293^{\circ}K)}{(0.0038^{\circ}K^{-1})}=556^{\circ}K=283^{\circ}C$

3 0

3 years ago

An arrow is launched upward with an initial speed of 100 meters per second (m/s). The equations above describe the constant-acce

ankoles [38]

Answer:

d=510.2m

t=10.2s

Explanation:

The formulas for accelerated motion are:

$v=v_0+at\\x=x_0+v_0t+\frac{at^2}{2}$

From them we can get $v^2=v_0^2+2ad$ .

We have:

$v-v_0=at\\t=\frac{v-v_0}{a}$

And substitute:

$x=x_0+v_0(\frac{v-v_0}{a})+\frac{a}{2}(\frac{v-v_0}{a})^2\\x-x_0=\frac{v_0(v-v_0)}{a}+\frac{(v-v_0)^2}{2a}$

We multiply both sides by 2a, and continue:

$2a(x-x_0)=2v_0(v-v_0)+(v-v_0)^2=2v_0v-2v_0^2+v^2+v_0^2-2vv_0=v^2-v_0^2$

Being d the displacement $x-x_0$ , we have $v^2=v_0^2+2ad$

For our exercise, we will write this as:

$d=\frac{v^2-v_0^2}{2a}$

And taking upwards direction positive and imposing final velocity 0m/s (for maximum height), we have:

$d=\frac{-v_0^2}{2a}=\frac{-(100m/s)^2}{2(-9,8m/s^2)}=510.2m$

For the time we use:

$t=\frac{v-v_0}{a}=\frac{-v_0}{a}=\frac{-(100m/s)}{(-9.8m/s^2)}=10.2s$

6 0

3 years ago

A wave that is traveling fast can be said to have a high ___

S_A_V [24]

A wave that is traveling fast can be said to have a high speed.<em> (b) </em>

Just like a car, motorcycle, or freight train that is traveling fast.

3 0

3 years ago