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3 years ago

When designing an experiment, why is it important to test only one variable?

Physics

2 answers:

m_a_m_a [10]3 years ago

6 0

That's the only way you can get consistent and accurate results.

zheka24 [161]3 years ago

6 0

I will try to explain more in depth. Lets say Jimmy frequently has headaches and needs medicine to treat it. Jimmy uses Headfix and Achefix both in one experiment. The next day, Jimmy feels great. His headaches are cured, but since Jimmy used 2 variables (the 2 medicines), he is left with three options

a. Headfix worked
b. Achefix worked
c. Both worked.

Now Jimmy has no idea what solved his problem. It could be 3 possible answers. However, if he used one variable at a time and had two experiments instead, lets see what happens.

Jimmy uses Headfix.
a. It worked
b. It didn't work

Headfix did not work.

Next experiment Jimmy uses Achefix
a. It worked
b. It didn't work

Achefix worked.

Now instead of having three possible solutions, you have 1 definite answer experiment. Therefore you cannot use more than one variable because there could be multiple outcomes and you do not know which variable affected the results differently/

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Explain how the extension of a spring is determined

fgiga [73]

Answer:

For a given spring the extension is directly proportional to the force applied For example if the force is doubled, the extension doubles When an elastic object is stretched beyond its limit of proportionality the object does not return to its original length when the force is removed

Explanation:

6 0

3 years ago

A student practicing for track ran 800 meter in 110 seconds. what was her speed?

adoni [48]

Her speed was 7.27 meters per second

3 0

3 years ago

Starting at 1.0 m/s, a cheetah runs with a constant acceleration for 4.8 s reaching a speed of 28 m/s. What is the acceleration

LenaWriter [7]

Answer:

c. $5.6m/s^2$

Explanation:

Initial velocity of cheetah,u=1 m/s

Time taken by cheetah =4.8 s

Final velocity of cheetah,v=28 m/s

We have to find the acceleration of this cheetah.

We know that

Acceleration, $a=\frac{v-u}{t}$

Where v=Final velocity of object

u=Initial velocity of object

t=Time taken by object

Using the formula

Then, we get

Acceleration, a= $\frac{28-1}{4.8}=\frac{27}{4.8} m/s^2$

Acceleration= $a=5.6 m/s^2$

Hence, the acceleration of cheetah= $5.6m/s^2$

5 0

3 years ago

What characteristics determine how easily two substances change temperature

ValentinkaMS [17]

Answer;

Amount of time the two substances are in contact

Area in contact between the two substances

Specific heat of the material that makes up the substances

Explanation;

The change in temperature of a substance is caused by heat energy. The change in temperature will depend on factors such as mass of the substance, the type of material it is made from, the time taken , specific heat of the material that makes the substance, and also the area of contact.

The amount of time the two substances are in contact affect the change in temperature such that if the two bodies are in contact for a longer time then a bigger change in temperature will be observed.

Specific heat capacity also determines the change in temperature that will be observed, such that a substance with a bigger specific heat capacity will record a small change in temperature.

7 0

3 years ago

A spherical asteroid of average density would have a mass of 8.7×1013kg if its radius were 2.0 km. 1. If you and your spacesuit

Law Incorporation [45]

1. 0.16 N

The weight of a man on the surface of asteroid is equal to the gravitational force exerted on the man:

$F=G\frac{Mm}{r^2}$

where

G is the gravitational constant

$M=8.7\cdot 10^{13}kg$ is the mass of the asteroid

m = 100 kg is the mass of the man

r = 2.0 km = 2000 m is the distance of the man from the centre of the asteroid

Substituting, we find

$F=(6.67\cdot 10^{-11}m^3 kg^{-1} s^{-2})\frac{(8.7\cdot 10^{13} kg)(110 kg)}{(2000 m)^2}=0.16 N$

2. 1.7 m/s

In order to stay in orbit just above the surface of the asteroid (so, at a distance r=2000 m from its centre), the gravitational force must be equal to the centripetal force

$m\frac{v^2}{r}=G\frac{Mm}{r^2}$

where v is the minimum speed required to stay in orbit.

Re-arranging the equation and solving for v, we find:

$v=\sqrt{\frac{GM}{r}}=\sqrt{\frac{(6.67\cdot 10^{-11} m^3 kg^{-1} s^{-2})(8.7\cdot 10^{13} kg)}{2000 m}}=1.7 m/s$

3 0

3 years ago