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3 years ago

Add or subtract as indicated.

1 answer:

4 0

In order to add or subtract numbers expressed in scientific notation, it is important that the powers of 10 in the numbers should have the same index or else you cannot readily add or ubtract these numbers. We do as follows:<span>
a. 5.80 x 10^9 s +3.20 x 10^8 s
We need to adjust one of the numbers since they do not have the same indices. We move one place to the left of the second number making it .320 x 10^9 s. Then, we can add the numbers now:

</span>5.80 x 10^9 s +.320 x 10^9 s = 6.12 x 10^9 s<span>

b. 4.87 x 10^-6 m - 1.93 x 10^-6 m

We can subtract the numbers directly since they have the same indices.

</span>4.87 x 10^-6 m - 1.93 x 10^-6 m = 2.94 x 10^-6 m

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A wire has resistivity of 0.12 homes per metre.

gulaghasi [49]

Answer:

(a) The resistance of 25m of wire is 3 ohms

(b) the length of this wire that has resistance 22 ohms is 183.33 m

Explanation:

Given;

resistivity of the wire, ρ = 0.12 ohms per meter

(a) The resistance of 25m of wire is calculated as follows;

$R = \rho L\\\\R = 0.12 \ \frac{ohms}{m} \times 25\ m\\\\R = 3 \ ohms$

(b) the length of this wire that has resistance 22 ohms is calculated as;

$L = \frac{R}{\rho} \\\\L = \frac{22 \ ohms }{0.12 \ ohms/m} = 183.33 \ m$

3 0

3 years ago

The robot HooRU is lost in space, floating around aimlessly, and radiates heat into the depths of the cosmos at the rate of 13.1

ahrayia [7]

Answer:

The temperature is $T = 168.44 \ K$

Explanation:

From the question ewe are told that

The rate of heat transferred is $P = 13.1 \ W$

The surface area is $A = 1.55 \ m^2$

The emissivity of its surface is $e = 0.287$

Generally, the rate of heat transfer is mathematically represented as

$H = A e \sigma T^{4}$

=> $T = \sqrt[4]{\frac{P}{e* \sigma } }$

where $\sigma$ is the Boltzmann constant with value $\sigma = 5.67*10^{-8} \ W\cdot m^{-2} \cdot K^{-4}.$

substituting value

$T = \sqrt[4]{\frac{13.1}{ 0.287* 5.67 *10^{-8} } }$

$T = 168.44 \ K$

7 0

3 years ago

A bicycle has a momentum of 23.4

Snowcat [4.5K]

Momentum=23.4kgm/s
Velocity=2m/s

$\\ \rm\longmapsto Momentum=Mass\times velocity$

$\\ \rm\longmapsto Mass=\dfrac{Momentum}{Velocity}$

$\\ \rm\longmapsto Mass=\dfrac{23.4}{2}$

$\\ \rm\longmapsto Mass=11.7kg$

4 0

3 years ago

A torque of 0.77 N⋅m is applied to a bicycle wheel of radius 30 cm and mass 0.70 kg

Naddik [55]

Answer:

α = τ/I = 0.77 / (0.70(0.30²)) = 12.22222... = 12 rad/s²

Explanation:

4 0

3 years ago

How much heat will be needed to warm 187 grams of water from 10 0C to 90 0C?

kvv77 [185]

<h3>Hello there!</h3>

Here, you are looking for the amount of heat put in for water, at a mass of 187 grams, to change by 80 degrees.

The equation commonly accepted to find the answer to questions like these is the specific heat formula.

The equation is Q = mc∆T, where Q is the amount of energy put in to raise the temperature by a certain amount, m is the mass, c is the specific heat capacity, and ΔT is the amount of temperature change.

The information given:

m = 187 grams

c = specific heat capacity of water, or in this case 1 calorie, or 4.184 joules (which is what we will be using)

ΔT = 80 degrees

Now just plug everything in to solve.

Q = 187 * 4.184 * 80

Q = 62592.64

So you have your answer: 62592.64 joules.

Hope this helped!

5 0

3 years ago