1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
shutvik [7]
3 years ago
5

Students are experimenting with a substance that they think can be added to soil to increase the number of flowers a certain pla

nt will make. They set up 20 pots of soil, each planted with the same type of seed. They divide the pots into two groups and add 15 drops of the substance to pots in one group and only 10 drops to pots in the other group. After the plants grow for four weeks, the students count how many flowers each plant has made.
What does this experimental investigation lack?

a control group
an independent variable
a dependent variable
a procedure

TROLL ANSWERS WILL BE REPORTED
Physics
2 answers:
professor190 [17]3 years ago
7 0

sorry if im incorrect. I believe its a dependent variable

pashok25 [27]3 years ago
3 0

Sorry if this isn't correct as it's been quite a while since i've learned this subject but I believe that the answer is dependant variable because the dependant variable would be the number of flowers on the plants and everything else seems to be in check

You might be interested in
Electric resistance ____________ with a(n) ____________in the length of a wire and as a result current flow ___________.
maria [59]
The answer is D. Electric resistance increases with an increase in the length of a wire and as a result current flow decreases. There is a direct relationship between the length of the wire and the resistance. The longer the wire, the more resistance there will be. Additionally, from Ohm's Law, current is inversely proportional to resistance. This means as the current increases, resistance decreases or vice versa.
3 0
2 years ago
A cake is removed from a 350◦F oven and placed on a cooling rack in a 70◦F room. After 30 minutes the cake is 200◦F. When will i
galben [10]

Answer:

350 F to 100 F it take approx 87.33 min  

Explanation:

given data

oven = 350◦F

cooling rack = 70◦F

time = 30 min

cake = 200◦F

solution

we apply here Newtons law of cooling  

\frac{dT}{dt} = -k(T-Ta)

\frac{dy}{dt} = \frac{d}{dt} (T(t) -Ta)

= \frac{dT}{dt} -\frac{dTa}{dt} =\frac{dT}{dt} = -k(T-Ta)

-ky \frac{dy}{dt} = -ky

T(t) -Ta = (To -Ta) e^{-kt} T(t) = Ta+ (To -Ta)  e^{-kt}

put her value for time 30 min and T(t) = 200◦F and To =350◦F  and Ta = 70◦F

so here

200 = 70 + ( 350 - 70 ) e^{-k30}

k = 0.025575

so here for  T(t) = 100F

100 = 70 + ( 350 - 70 ) e^{-0.025575*t}

time = 87.33 min

so here 350 F to 100 F it take approx 87.33 min  

5 0
3 years ago
Two insulated wires, each 2.64 m long, are taped together to form a two-wire unit that is 2.64 m long. One wire carries a curren
nikklg [1K]

Answer:

4.77\ \text{A}

Explanation:

F = Magnetic force = 4.11 N

I_n = Net current

I_2 = Current in one of the wires = 7.68 A

B = Magnetic field = 0.59 T

\theta = Angle between current and magnetic field = 65^{\circ}

l = Length of wires = 2.64 m

I = Current in the other wire

Magnetic force is given by

F=I_nlB\sin\theta\\\Rightarrow I_n=\dfrac{F}{lB\sin\theta}\\\Rightarrow I_n=\dfrac{4.11}{2.64\times 0.59 \sin65^{\circ}}\\\Rightarrow I_n=2.91\ \text{A}

Net current is given by

I_n=I_2-I\\\Rightarrow I=I_2-I_n\\\Rightarrow I=7.68-2.91\\\Rightarrow I=4.77\ \text{A}

The current I is 4.77\ \text{A}.

8 0
2 years ago
Which type of radiation can reach the furthest?<br> A. Beta<br><br> B. Gamma<br><br> C. Alpha
Mashutka [201]

Answer:

C. Alpha

Explanation:

Gamma radiation, unlike alpha or beta, does not consist of any particles, instead consisting of a photon of energy being emitted from an unstable nucleus. Having no mass or charge, gamma radiation can travel much farther through air than alpha or beta, losing (on average) half its energy for every 500 feet.

7 0
3 years ago
Read 2 more answers
What type of energy does a pv cell create ?
Alex_Xolod [135]

Answer:  Solar Photovoltaic (PV) cells generate electricity by absorbing sunlight and using that light energy to create an electrical current. There are many PV cells within a single solar panel, and the current created by all of the cells together adds up to enough electricity to help power your school, home and businesses.

                              <em>--Cited from </em><u><em>Solar Schools</em></u>

6 0
1 year ago
Read 2 more answers
Other questions:
  • A teacher discusses a scientific theory that has been in place for almost a century. which would present the greatest challenge
    13·2 answers
  • Carbon-14 is a naturally-occuring, stable isotope that is commonly used is scientific studies as a tracer and to date artifacts.
    13·2 answers
  • Two pianos each sound the same note simultaneously, but they are both out of tune. On a day when the speed of sound is 343 m/s,
    13·1 answer
  • What is the maximum mass that can hang without sinking from a 20-cm diameter Styrofoam sphere in water? Assume the volume of the
    14·1 answer
  • What is the origin of magma
    8·2 answers
  • The action of property being taken directly from a person or in that person's presence must be an element in which type of crime
    6·1 answer
  • A small rubber ball is launched by a compressed-air cannon from ground level with an initial speed of 17.3 m/s directly upward.
    15·1 answer
  • A point charge is placed 3 m from a 4 uC charge. What is the strength of the electric field on the point charge at this
    12·2 answers
  • Which type of telescope is best used to detect distant planets?​
    12·1 answer
  • The constellation Canis Minor has a binary star system consisting of Procyon A and Procyon B. Procyon A, at 3×1030kg, has 2.5 ti
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!