What net force is required to accelerate a car at a rate of 2 m/s2 if the car has a mass of 3,000 kg?

Describe at least two ways that you can reduce the friction between two solid surfaces

Firlakuza [10]

I will try to name as much as I can :

• Magnets
• Butter
• Petroleum
• Using a spherical object leaves the surface with very little surface area, basically using balls will help alot
• Using a hockey table leaves you with not friction at all when on

8 0

4 years ago

I have an object that I want to know when it was made. I calculate that the object contains 0.12g of Iodine-131 but started with

Sav [38]

Answer: 71.72 days

Explanation:

This problem can be solved using the <u>Radioactive Half Life Formula: </u>

$A=A_{o}.2^{\frac{-t}{h}}$ (1)

Where:

$A=0.12 g$ is the final amount of Iodine-131

$A_{o}=60 g$ is the initial amount of Iodine-131

$t$ is the time elapsed

$h=8 days$ is the half life of Iodine-131

Knowing this, let's substitute the values and find $t$ from (1):

$0.12 g=(60 g)2^{\frac{-t}{8 days}}$ (2)

$\frac{0.12 g}{60g}=2^{\frac{-t}{8 days}}$ (3)

Applying natural logarithm in both sides:

$ln(\frac{0.12 g}{60g})=ln(2^{\frac{-t}{8 days}})$ (4)

$-6.21=-\frac{t}{8 days}ln(2)$ (5)

Finding $t$ :

$t=71.72 days$

7 0

4 years ago

A person stands between two speakers driven by the same source. Each speaker produces a tone with a frequency of 200 Hz on a day

MissTica

Answer:

The type of interference the person perceives is a Constructive Interference

Explanation:

Before we solve the problem we need to clarify some concepts:

There are two types of Interference, the Constructive and the Destructive interference

The Constructive Interference happens if the difference between the waves movement is equal to an even semi-wavelength number

The Destructive Interference is the opposite than the Constructive Interference, it happens if the difference between the waves movement is equal to an odd semi-wavelength number

Taking the above into account let´s proceed to solve the problem.

First, we will need to find how much the wavelength is (we will call it l), we know the frequency f=200Hz, we also know the speed of sound is v=330m/s. We will use the next equation:

$l=v/f$ then we get that $l=1.65m$

In order to find the semi-wavelength we must divide by 2 the previous result, in this case the semi-wavelength will be:

$l/2=0.825m$

Now, we find the difference between the waves movement, which is the difference between both distances, this difference will be called d and we will find it this way:

$d=4.95m-1.65m$ then d=3.3m

After this, we will do a relation between the distance and the semi-wavelength in order to find what type of interference the person perceives, this way:

$(d)/(l/2)$ then, we have a relation equals to 4. As it´s an even number, we determine the interference is a Constructive Interference

8 0

4 years ago

Maggie is using her cat in an experiment on animal intelligence. Which of the following statements is true?

Kamila [148]

1. If Maggie gives her cat an unfair advantage, her experimental results will be biased.

Explanation:

Maggie using her cat in the experiment to test for intelligence gives the cat an unfair advantage, her experimental results will be biased.

Due to her emotional attachment with the cat, the experimental results will be skewed to portraying her cat as intelligence.
This is not a good experiment to carry out.
Such an experiment should be carried out with an unknown cat.

learn more:

Experiment brainly.com/question/1621519

#learnwithBrainly

6 0

3 years ago

An overnight rainstorm has caused a major roadblock. Three massive rocks of mass m1=584 kg, m2=838 kg, and m3=322 kg have blocke

Elena-2011 [213]

Answer:

Force must be applied to m₁ to move the group of rocks from the road at 0.250 m/s² = 436 N

Explanation:

Total force required = Mass x Acceleration,

F = ma

Here we need to consider the system as combine, total mass need to be considered.

Total mass, a = m₁+m₂+m₃ = 584 + 838 + 322 = 1744 kg

We need to accelerate the group of rocks from the road at 0.250 m/s²

That is acceleration, a = 0.250 m/s²

Force required, F = ma = 1744 x 0.25 = 436 N

Force must be applied to m₁ to move the group of rocks from the road at 0.250 m/s² = 436 N

8 0

3 years ago