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4 years ago

What is the control group used for

Physics

1 answer:

LUCKY_DIMON [66]4 years ago

6 0

Answer:

What is a Control Group? The control group (sometimes called a comparison group) is used in an experiment as a way to ensure that your experiment actually works. It's a way to make sure that the treatment you are giving is causing the experimental results, and not something outside the experiment

Explanation:

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AP Physics I, shouldn't be too hard.

Nana76 [90]

Answer:

The correct option is;

D. The kinetic energy decreases by 3·m₀·v₀²

Explanation:

The given parameters are;

The mass of object X = m₀

The initial velocity of object X = v₀

The mass of object Y = 2·m₀

The initial velocity of object Y = -2·v₀

By conservation of linear momentum, we have;

The total initial momentum = The total final momentum

Therefore, we have;

The total initial momentum = m₀·v₀ - 2·m₀·2·v₀ = The total final momentum

∴ The total final momentum = -3·m₀·v₀

The total mass of the two object after sticking together = 2·m₀ + m₀ = 3·m₀

Therefore, the velocity of the two objects after collision = (The total final momentum)/(Total mass) = -3·m₀·v₀/(3·m₀) = -v₀

The kinetic energy = 1/2 × Mass × (Velocity)²

Therefore, the kinetic energy after collision = 1/2 × (3·m₀) × v₀² = 3·m₀·v₀²/2

The kinetic energy before collision = 1/2 × m₀ × v₀² + 1/2 × (2·m₀) × (2·v₀)² = (1/2 + 4) × (m₀·v₀²)

∴ The kinetic energy before collision = 9·(m₀·v₀²)/2

The change in kinetic energy = The kinetic energy after collision - The kinetic energy before collision = 3·m₀·v₀²/2 - 9·(m₀·v₀²)/2 = -3·m₀·v₀²

Therefore, the kinetic energy decreases by 3·m₀·v₀².

5 0

3 years ago

if you throw a rock straight up at a speed of 19m/s. How long goes it take the ball to reach its maximum height?

Scrat [10]

Answer:

It requires 1.9 seconds to reach maximum height.

Explanation:

As per given question,

Initial velocity (U) =19 m/s

Final velocity (V) = 0 m/s

$\text { Taking acceleration due to gravity }(a)=10 \mathrm{m} / \mathrm{s}^{2}$

Maximum height = S

Time taken is "t"

Calculating time taken to reach maximum height:

We know that time taken to reach the maximum height is calculated by using the formula V = U + at

Substitute the given values in the above equation.

Final velocity is “0” as there is no velocity at the maximum height.

$0=19+10 \times t$

$-19=10 \times t$

$\frac{-19}{10}=t$

t = 1.9 seconds.

The time taken to reach maximum height is 1.9 seconds.

Calculating maximum height:

$\text { Consider the equation } V^{2}-U^{2}=2 a S$

Solving the equation we will get the value of S

$0-19^{2}=2 \times(-10) \times \mathrm{S} .(-\text { is due to opposite of gravity) }$

-361 = -20S

Negative sign cancel both the sides.

$\mathrm{S}=\frac{361}{20}$

S = 18.05 m

Maximum height is 18.05 m .

3 0

3 years ago

An arrow is shot vertically upward at a rate of 250ft/s. Use the projectile formula h=−16t2+v0t to determine at what time(s), in

SIZIF [17.4K]

Answer:

The arrow is at a height of 500 feet at time t = 2.35 seconds.

Explanation:

It is given that,

An arrow is shot vertically upward at a rate of 250 ft/s, v₀ = 250 ft/s

The projectile formula is given by :

$h=-16t^2+v_ot$

We need to find the time(s), in seconds, the arrow is at a height of 500 ft. So,

$-16t^2+250t=500$

On solving the above quadratic equation, we get the value of t as, t = 2.35 seconds

So, the arrow is at a height of 500 feet at time t = 2.35 seconds. Hence, this is the required solution.

6 0

4 years ago

Read 2 more answers

What are limits that would be age appropriate for teens vs toddlers? give me some examples of limits that you may have for a tee

Pavlova-9 [17]

The limits which would be age appropriate for toddlers include being flexible and realistic while that of a teen should be more rigid.

<h3>Who are Toddlers?</h3>

This refers to a child whose age ranges from 1 year to 4 years and limits set for them should be flexible due to it helping them feel more secure and decreases anxiety.

Example of limits that you may have for a teen is reducing their screen time while an example of limits for toddlers is correcting their junk eating habits. Teens should have a rigid limit so as to enable them do the right things at all times due to their strong emotions.

Read more about Limits here brainly.com/question/1419949

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6 0

2 years ago

Difference between elastic and inelastic collisions

Eva8 [605]

An elastic collision is where there is no loss of kinetic energy in the collision. Momentum is conserved saved in inelastic collisions, but cannot track the kinetic energy through the collision since some of it is changed into other forms of energy.

3 0

3 years ago