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4 years ago

A ball rolls forward in the grass slowing down as it rolls?

Physics

1 answer:

olga nikolaevna [1]4 years ago

3 0

Yes it does, uh huh. It slows down as it rolls. That's a fact.

In order for the ball to roll forward, it has to push grass out of the way. That takes energy. To bend each blade of grass out of its way, the ball has to use a tiny bit of the kinetic energy that it has, so it gradually runs out of kinetic energy. When its kinetic energy is all gone, it stops moving.

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g a stone with mass m=1.60 kg IS thrown vertically upward into the air with an initial kinetic energy of 470 J. the drag force a

otez555 [7]

Answer:

Height reached will be 28.35 m

Explanation:

Here we can use the work energy theorem to find the maximum height

As we know by work energy theorem

Work done by gravity + work done by friction = change in kinetic energy

$-mgh - F_f h = 0 - \frac{1}{2}mv_i^2$

now we will have

$-1.60(9.8)(h) - 0.900(h) = - 470$

$-16.58 h = -470$

$h = 28.35 m$

so here the height raised by the stone will be 28.35 m from the ground after projection in upward direction

5 0

3 years ago

Please help ASAP! Thank you! Brainliest!!!

UNO [17]

As a transformer generates ac current of different voltage when the switch is closed and the current flows in the primary coil which induces a magnetic field.

Answer: Option 2

<u>Explanation:</u>

A transformer is an electric device which can vary the potential differences or voltages of an alternating current. It's a simple device composed of an iron core, a primary and the secondary current conducting coil.

The primary coil is attached to the switch which provides ac current through potential difference. Now this current induces a magnetic field in the iron core. When the voltage of this ac current is varied, the magnetic field varies and starts inducing ac current of different voltage in the secondary coil.

Thus, an AC current of different voltage flows in the secondary coil that can be used in small electric devices. This is how a transformer works. There are two kinds of transformers- Step Up and Step Down. A step up transformer increases the potential difference whereas the step down does the opposite.

3 0

3 years ago

A thin insulating rod is bent into a semicircular arc of radius a, and a total electric charge Q is distributed uniformly along

storchak [24]

Answer:

$v = \frac{kQ}{a}$

Explanation:

We define the linear density of charge as:

$\lambda = \frac{Q}{L}$

Where L is the rod's length, in this case the semicircle's length L = πr

The potential created at the center by an differential element of charge is:

$dv = \frac{kdq}{r}$

where k is the coulomb's constant

r is the distance from dq to center of the circle

Thus.

$v = \int_{}^{}\frac{kdq}{a}$

$v = \frac{k}{a}\int_{}^{}dq$

$v = \frac{kQ}{a}$ Potential at the center of the semicircle

4 0

3 years ago

Which requires more work, increasing a car's speed from 0 mph to 30 mph or from 50 mph to 60 mph?

Gnom [1K]

Increasing a car's speed from 0 mph to 30 mph requires more work than that of 50 mph to 60 mph.

Work is a measure of energy expended in moving an object. It is calculated by multiplying the force by the distance.

According to this question, work is required to move a car from one position to another.

The distance moved from 0 - 30mph is more than that moved from 50 - 60mph, therefore, increasing a car's speed from 0 mph to 30 mph requires more work than that of 50 mph to 60 mph.

Learn more about work at: brainly.com/question/19382352

#SPJ1

8 0

2 years ago

Two loudspeakers, 5.5 m apart and facing each other, play identical sounds of the same frequency. You stand halfway between them

zhuklara [117]

Answer:

a) f = 809.5 Hz , b) f = 1619 Hz

Explanation:

The condition for destructive interference from the speakers is

Δr / lam = Ф / 2π

λ = Δr 2π / π

We substitute

λ = 0.21 2 π/π

Lam = 0.42 m

Now let's use the ratio of the speed of sound and the wavelength and the frequency

v = λ f

f = v /λ

f = 340 / 0.42

f = 809.5 Hz

b) in this case the intensity is maximum

Lam = Δr 2π / 2π

Lam = 0.21 m

fF= v / lam

f = 340 / 0.21

f = 1619 Hz

3 0

4 years ago