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3 years ago

Select the correct answer.

Physics

1 answer:

Kipish [7]3 years ago

4 0

Answer:

ОА.

The net force acting on the car from all directions is zero.

Explanation:

Constant speed along a straight line

It means constant magnitude of velocity without chainging direction

It means constant velocity. Which means acclecration is zero

By Newton's second law:

$F=ma$

Net force is also zero

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A piano wire with mass 2.60g and length 84.0 cm is stretched with a tension of 25.0 N. A wave with frequency 120.0 Hz and amplit

likoan [24]

Answer:

Power will be 0.2023 watt

And when amplitude is halved then power will be 0.0505 watt

Explanation:

We have given mass of the Piano wire m = 2.60 gram = 0.0026 kg

Length of wire l = 84 cm = 0.84 m

So mass density $\mu =\frac{m}{l}=\frac{0.0026}{0.84}=0.0031kg/m$

Tension in the wire T = 25 N

Frequency f = 120 Hz

So angular frequency $\omega =2\pi f=2\times 3.14\times 120=753.6rad/sec$

And amplitude A = 1.6 mm = 0.0016 m

We have to find the generated power

Power is given by $P=\frac{1}{2}\sqrt{\mu T}\omega ^2A^2=\frac{1}{2}\times \sqrt{0.0031\times 25}\times 753.6^2\times 0.0016^2=0.2023watt$

From the relation we can see that power $P\ \propto\ A^2$

So if amplitude is halved then power will be $\frac{1}{4}$ times

So power will be equal to $\frac{0.2023}{2}=0.0505watt$

4 0

3 years ago

If you could go a year into the future, or 3 seconds into the past, where would you go? What date? I would go to June 6th, 2018

vova2212 [387]

Idk I would go back to pre-k

8 0

3 years ago

A 7.7 kg sphere makes a perfectly inelastic collision with a second sphere initially at rest. The composite system moves with a

klemol [59]

Answer:

15.4 kg.

Explanation:

From the law of conservation of momentum,

Total momentum before collision = Total momentum after collision

mu+m'u' = V(m+m').................... Equation 1

Where m = mass of the first sphere, m' = mass of the second sphere, u = initial velocity of the first sphere, u' = initial velocity of the second sphere, V = common velocity of both sphere.

Given: m = 7.7 kg, u' = 0 m/s (at rest)

Let: u = x m/s, and V = 1/3x m/s

Substitute into equation 1

7.7(x)+m'(0) = 1/3x(7.7+m')

7.7x = 1/3x(7.7+m')

7.7 = 1/3(7.7+m')

23.1 = 7.7+m'

m' = 23.1-7.7

m' = 15.4 kg.

Hence the mass of the second sphere = 15.4 kg

7 0

3 years ago

Read 2 more answers

R'=2 Ohm R"=1,5 Ohm R"'=2 Ohm

Andrew [12]

Answer:

2.5 ohm

Explanation:

R' and R''' are parallel

So,

1/R1= 1/R' + 1/R'''

1/R1 = 1/2 + 1/2

1/R1 = 1

so,

R1= 1 ohm

Now R1 and R'' are in series

so,

R= R1 + R''

R= 1 + 1.5

R= 2.5 ohm

5 0

2 years ago

The acclaimed environmental book, Silent Spring, was written by this woman in 1962.

olga_2 [115]

Rachel Carson was the author of the acclaimed environmental book, Silent Spring. The book was published in 1962.
It documented the negative effect that synthetic pesticides have on the environment, specifically on birds.
This book laid bare to the American public what chemical companies indirectly contributed to the environment.
The public furor this book caused led to the reversal of the national pesticide policy, a nationwide ban on DDT for agricultural uses, and inspired the creation of the U.S. Environmental Protection Agency.

7 0

3 years ago