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]
4 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]4 years ago
7 0

sorry if im incorrect. I believe its a dependent variable

pashok25 [27]4 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
The orbital period of a satellite is 2 × 106 s and its total radius is 2.5 × 1012 m. The tangential speed of the satellite, writ
LenaWriter [7]

The orbital period of the satellite[T] is given as 2*10^{6} S.

The radius of the satellite is given [R] 2.5*10^{12} m.

we are asked here to calculate the tangential speed of the satellite.

Before going to get the solution first we have understand the tangential speed.

The tangential speed of a satellite is given as the speed required to keep the satellite along the orbit. If satellite speed is less than tangential speed,there is the chance of it falling down towards earth. If it is more,then it will deviate from it orbit and can't stick to the orbit further.In a simple way  the tangential speed is the linear speed of an object in a circular path.

Now we have to calculate the tangential speed [V].

Mathematically the tangential speed [V]   written as -

                                V=\frac{2\pi R}{T}

where T is the time period of the satellite and R is the radius of the satellite.

                        V=\frac{2*3.14*10^{12} }{2*10^{6} }

                               = 7.85*10^{6} m/s

There is also another way through which we can get  the solution as explained below-

We know that the tangential speed of a satellite V=\sqrt{\frac{GM}{R^{2} } }

where G is the gravitational constant and M is the mas of central object.

But we know that g=\frac{GM}{R^{2} }

                               ⇒GM=gR^{2}  where g is the acceleration due to gravity of that central object.


Hence    V=\sqrt{\frac{gR^{2} }{R} }

               ⇒   V=\sqrt{gR}

By knowing the value of g due to that central object we can also calculate its tangential speed.

                           

 




7 0
3 years ago
Read 2 more answers
A 33.0 g iron rod, initially at 22.7 ∘c, is submerged into an unknown mass of water at 63.3 ∘c, in an insulated container. the f
professor190 [17]
When the iron and the water reach thermal equilibrium, they have same temperature, T=58.5^{\circ}C.
We can consider this as an isolated system, so the heat released by the water is equal to the heat absorbed by the iron.

The hear released by the water is:
Q_w =m_w C_{sw} \Delta T_w
where m_w is the water mass, C_{sw}=4.186 J/(g^{\circ}C) is the specific heat of the water, and \Delta T_w = 63.6^{\circ}-58.5^{\circ}=5.1^{\circ}C is the variation of temperature of the water.

Similarly, the heat absorbed by the iron is:
Q_i = m_i C_{si} \Delta T_i
where m_i = 33.0 g is the iron mass, C_{si}=0.444 J/(g^{\circ}C) is the iron specific heat, and \Delta T_i = 58.5^{\circ}-22.7^{\circ}=35.8^{\circ}C is the variation of temperature of the iron.

Writing Q_w=Q_i and replacing the numbers, we can solve to find mw, the mass of the water:
m_w= \frac{m_i C_{si} \Delta T_i}{C_{sw} \Delta T_w} =24.6 g
4 0
3 years ago
Consider the following 3 cases. (1) A block initially at rest on a floor is given a quick push by a hand. (2) The hand does not
jek_recluse [69]

Answer:

(1) The block isn't moving, despite the hand's force on it.

  • The net force on the block is zero.
  • The acceleration of the block is also zero.

(2) The block is gradually slowing down as it slides across the floor.

  • The acceleration of the block points in the opposite direction of the block's movement (i.e., the opposite direction of the block's velocity.)
  • The net force on the block points in the opposite direction of the block's movement. (Same direction as the block's acceleration.)

(3) Once again, the block is not moving.

  • The net force on the block is zero.
  • The acceleration of the block is also zero.

Explanation:

By Newton's Second Law, the net force on an object is in the same direction as its acceleration. Since this question said a lot about the object's motion, the direction of the object's acceleration might be easier to find than its net force.

<h3>(1)</h3>

The acceleration of an object is the rate of change of its velocity over time.

In this situation, the velocity of the object is zero, which is itself a constant. As a result, the rate of change of the object's velocity over time would be zero. Hence, the acceleration of the object would also be equal to zero. The zero vector doesn't have a specific direction.

By Newton's Second Law, the net force on the object is proportional to its acceleration. As a result, the net force on the object in this case would also be equal to zero. What about the hand's force on the block? The friction and normal force from the ground balances that force while the block hasn't yet started to move.

<h3>(2)</h3>

The object is slowing down over time. In other words, its velocity is decreasing over time. When a scalar value is decreasing, its rate of change would be negative. However, since velocity and acceleration are vectors, the acceleration of the object would be in the opposite direction of its velocity.

The net force on an object is in the same direction as its acceleration. As a result, the net force on this block in this case would also be in the opposite direction of the block's velocity.

<h3>(3)</h3>

Similar to the first situation, since the velocity of the block is zero (a constant,) its acceleration would be equal to zero. Since the net force on an object is proportional to its acceleration, the net force on this block would also be equal to zero.

7 0
3 years ago
A balloon is inflated from 0.0100 l to 0.400 l against an external pressure of 10.00 atm. how much work is done in joules? 101.3
Ganezh [65]
To calculate the work, we use:
W = PΔV
W = 10(0.4-0.01)
W = 3.9 L*atm
W = 3.9 * 101.3
W = 395.07 Joules
4 0
4 years ago
Read 2 more answers
A bullet travels at 850 m/s. how long will it take a bullet to go 1 km?
Mariana [72]
<span>(1KM x 1000M/KM)/ 850 M/s = 1.18 seconds</span>
8 0
4 years ago
Other questions:
  • Which of the following body systems work together to get sells the oxygen they need to carry at the cellular respiration
    12·1 answer
  • A battery operated DVD player uses 12 DV volts from AA batteries and draws a current of 3 A. Calculate the resistance.
    6·1 answer
  • HELP ASAP PLEASE HELP!
    8·2 answers
  • A 90-kg astronaut is stranded in space at a point 6.0 m from his spaceship, and he needs to get back in 4.0 min to control the s
    14·1 answer
  • In a physics lab, a 60-kg student runs up a 2.0-meter tall flight of stairs in 1.5 seconds. The work done to get to the top is 1
    11·1 answer
  • a water tank is 40m high and contains 4,000 kg of water .What is the gravitational potential energy of the water?show your work
    14·2 answers
  • According to Bohr each orbit an electron could travel in had a certain amount of ________ associated with it.
    13·2 answers
  • A remote-controlled, pilot-operated ___ valve is type of pilot-operated relief valve that uses one or more external pilot valves
    13·1 answer
  • Thought Experiment: A monkey escapes from a zoo and climbs a tree. After failing to entice the monkey down, a zookeeper fires a
    6·1 answer
  • What is 2+2 is 4 - 1 =??<br><br><br><br> Know your memes!
    5·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!