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2 years ago

In a typically constructed research study, the experimental group is selected:

Physics

1 answer:

blondinia [14]2 years ago

7 0

Answer:

D. from a separate pool than is the control group.

Explanation:

in the picture the person answers is backwards but...

hope this helps have a nice day

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How long will bus take to travel 150 km at an average speed of 40km/hr

romanna [79]

Answer:

3.75 hours

Explanation:

By $v = \frac{d}{t}$

where v is the velocity (or speed in this case)

d is the distance travelled

t is the time taken

$t = \frac{150}{40}=3.75$
Therefore it takes 3.75 hours for the bus to travel 150 km and 40 km/hr.

7 0

3 years ago

Backpackers often use canisters of white gas to fuel a cooking stove's burner. If one canister contains 1.45 L of white gas, and

lorasvet [3.4K]

Answer: One canister contains 1.03 Kg of fuel,

Explanation:

The density is defined as the relation between the mass and the volume $p=\frac{m}{v}$

First of all you need to have the same units for volume and density, so:

For the volume,

$1.45 L * \frac{1.10*10^{-3}m^{3} }{1 L} = 1.45 *10^{-3} m^{3}$

For the density,

$p = 0.710\frac{g}{cm^{3} } *\frac{1cm^{3} }{1*10^{-6}m^{3} }*\frac{1 Kg}{1*10^{3}g } = 710\frac{Kg}{m^{3} }$

From the density equation we have $m=p*v$ , so:

$710\frac{Kg}{m^{3} } *1.45*10^{-3} m^{3} = 1.03Kg$

4 0

4 years ago

Light-rail passenger trains that provide transportation within and between cities are capable of modest accelerations. The magni

Mkey [24]

During the first phase of acceleration we have:
v o = 4 m/s; t = 8 s; v = 13 m/s, a = ?
v = v o + a * t
13 m/s = 4 m / s + a * 8 s
a * 8 s = 9 m/s
a = 9 m/s : 8 s
a = 1.125 m/s²
The final speed:
v = ?; v o = 13 m/s; a = 1.125 m/s² ; t = 16 s
v = v o + a * t
v = 13 m/s + 1.125 m/s² * 16 s
v = 13 m/s + 18 m/s = 31 m/s

3 0

3 years ago

A uniformly charged rod (length = 2.0 m, charge per unit length = 3.0 nC/m) is bent to form a semicircle. What is the magnitude

Yuki888 [10]

Answer:

The magnitude of the electric field at the center of the circle is 85 N/C

The correct option is b. 85 N/C

Explanation:

Please see the attachments below

8 0

3 years ago

A radioactive isotope has a half-life of 5,000 years. A rock originally contained 16 grams of radioactive isotope, and now conta

mixas84 [53]

Answer:

10,000 years

Explanation:

Given that,

Half life of the radioactive isotope, $t_{\frac{1}{2}}$ = 5000 years

Initial composition, $N_0$ = 16 grams

Final composition, $N$ = 4 grams

We know that,

$N=N_0\times (\dfrac{1}{2})^\frac{t}{t_\frac{1}{2}}}\\\\4=16(0.5)^\frac{t}{5000}}\\\\\dfrac{4}{16}=(0.5)^{\frac{t}{5000}}\\\\0.25=(0.5)^\frac{t}{5000}\\\\0.5^2=(0.5)^\frac{t}{5000}\\\\2=\dfrac{t}{5000}\\\\t=2\times 5000\\\\t=10000\ yrs$

Therefore, the age of the rock is 10,000 years.

6 0

3 years ago