Ask question

Ask question

All categories

2 years ago

10

Vicky wanted to investigate water evaporation. She placed 50 mL of distilled water in three identical glass jars. She left one j

ar in the sunlight, one jar in the dark, and one jar in a shady area. After four hours, she measured how much water was still in each jar. Which of the following variables was held constant in the experiment? A. air temperature B. amount of water in jars at the end of the investigation C. light exposure D. amount of water placed in jars

2 answers:

IgorC [24]2 years ago

4 0

Answer:

D. the amount of water placed in jars

Explanation:

it was the same for all of the jars at the beginning

Korolek [52]2 years ago

3 0

D because it makes the most sense

You might be interested in

Est ce qu’un cricket c’est un consommateur

Sholpan [36]

Answer:

Oui

Explanation:

7 0

2 years ago

A uniform solid disk of mass 5.00 kg and diameter 47.0 cm starts from rest and rolls without slipping down a 40.0 ∘ incline that

saveliy_v [14]

Answer:

The speed it reaches the bottom is

$v=6.51m/s$

Explanation:

Given: $m=5.0kg$ , $r=47cm\frac{1m}{100cm}=0.47m$

Using the conservation of energy theorem

$U_i=K_E+K_{ER}$

$m*g*h=\frac{1}{2}*m*v^2+\frac{1}{2}*I*w^2$

$v=r*w$ , $I=\frac{1}{2}*m*r^2$

$m*g*h=\frac{1}{2}*m*(r*w)^2 +\frac{1}{2}*[\frac{1}{2} *m*r^2]*w^2$

$m*g*h=\frac{3}{4}*m*r^2*w^2$

$g*h=\frac{3}{4}*r^2*w^2$

Solve to w'

$w^2=\frac{4*g*h}{3*r^2}$

$h=x*sin(30)=6.5m*sin(30)=3.25m$

$w=\sqrt{\frac{4*9.8m/s^2*3.25m}{3*(0.235m)^2}}$

$w=27.74rad/s$

$v=27.74rad/s*0.235m=6.51m/s$

7 0

3 years ago

Which observational tool helped astronomers Arno Penzias and Robert Wilson discover the

iren2701 [21]

Answer:

A radio telescope helped the astronomers discover the CMB.

Explanation:

Penzias and Wilson while experimenting with a radio telescope in 1964, accidentally discovered the radiation that exists universally also known as the CMB.
This was used to support the "Big Bang Theory" and not the "Steady State Theory"
CMB is the faint cosmic radiation that fills up the universe. It provides important data for understanding early universe.
This data tells us about the composition of the universe and its age which raises new questions about the universe.

3 0

3 years ago

(1) Explain : Market and its characteristics.

AlekseyPX

Answer:

market is a place where we sell or buy things ( goods)

it's characteristics are

buying and selling goods

perfect competitions

market doesn't refer only a fix place

6 0

2 years ago

Water is drawn from a well in a bucket tied to the end of a rope whose other end wraps around a solid cylinder of mass 50 kg and

sleet_krkn [62]

Answer:

$\alpha=78.4\ rad.s^{-2}$

Explanation:

Given:

mass of solid cylinder, $m=50\ kg$

diameter of cylinder, $d=0.25\ m$

mass of bucket of water, $m_w=20\ kg$

<em>When the bucket is released to fall in the well, it fall under the acceleration due to gravity.</em>

We have formula for angular acceleration as:

$\alpha=\frac{g}{r}$

where:

g = acceleration due to gravity

r = radius of the cylinder

$\aplha=\frac{9.8}{0.125}$

$\alpha=78.4\ rad.s^{-2}$

4 0

2 years ago