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Harlamova29_29 [7]

3 years ago

5

To test the quality of a tennis ball, you drop it onto a floor from a height of 4.00m . It rebounds to a height of 2.00 m. If th

e ball is in contact with the floor for 12.0ms,
(a) What is the magnitude of its average acceleration during the contact?
(b) is the acceleration up or down?

1 answer:

mash [69]3 years ago

4 0

A. dont know
B. Up not down

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A particle with mass 1.09 kg oscillates horizontally at the end of a horizontal spring. A student measures an amplitude of 0.985

e-lub [12.9K]

Answer:

a) $f = 0.598\,hz$ , b) $v_{max} = 3.701\,\frac{m}{s}$ , c) $k = 15.385\,\frac{N}{m}$ , d) $U = 1.081\,J$ , e) $K = 6.382\,J$ , f) $v\approx 3.422\,\frac{m}{s}$

Explanation:

a) The frequency of oscillation is:

$f = \frac{76}{127\,hz}$

$f = 0.598\,hz$

b) The angular frequency is:

$\omega = 2\pi \cdot f$

$\omega = 2\pi \cdot (0.598\,hz)$

$\omega = 3.757\,\frac{rad}{s}$

Lastly, the speed at the equilibrium position is:

$v_{max} = \omega \cdot A$

$v_{max} = (3.757\,\frac{rad}{s} )\cdot (0.985\,m)$

$v_{max} = 3.701\,\frac{m}{s}$

c) The spring constant is:

$\omega = \sqrt{\frac{k}{m}}$

$k = \omega^{2}\cdot m$

$k = (3.757\,\frac{rad}{s} )^{2}\cdot (1.09\,kg)$

$k = 15.385\,\frac{N}{m}$

d) The potential energy when the particle is located 38.1 % of the amplitude away from the equilibrium position is:

$U = \frac{1}{2}\cdot (15.385\,\frac{N}{m} )\cdot (0.375\,m)^{2}$

$U = 1.081\,J$

e) The maximum potential energy is:

$U_{max} = \frac{1}{2}\cdot (15.385\,\frac{N}{m} )\cdot (0.985\,m)^{2}$

$U_{max} = 7.463\,J$

The kinetic energy when the particle is located 38.1 % of the amplitude away from the equilibrium position is:

$K = U_{max} - U$

$K = 7.463\,J - 1.081\,J$

$K = 6.382\,J$

f) The speed when the particle is located 38.1 % of the amplitude away from the equilibrium position is:

$K = \frac{1}{2}\cdot m \cdot v^{2}$

$v = \sqrt{\frac{2\cdot K}{m} }$

$v = \sqrt{\frac{2\cdot (6.382\,J)}{1.09\,kg} }$

$v\approx 3.422\,\frac{m}{s}$

4 0

3 years ago

Technician A says that power is the rate that energy is stored. Technician B says that power refers to the rate that energy is t

Alex777 [14]

Answer:

C. Both technicians A and B

Explanation:

From the physical definition, power is defined as the rate of a body doing work. It is expressed as

P = w/t watts

Where

w - is the work done or the energy of the system in joules

t - time

The unit of power is represented in watts.

Whenever there is a rate of change of energy in the system, it accounts for the efficiency of the power of the system.

Hence, the statements of both technicians are correct.

7 0

4 years ago

Which is required for

vaieri [72.5K]

Answer:

You need (B) Two substances in direct contact with one another to have conduction.

I hope this helped at all.

5 0

3 years ago

Do wormholes exist ?? is it possible to traverse to the other side of the universe ?

Nastasia [14]

Black holes is exists
Black holes is highly gravitional wave field in space

8 0

3 years ago

Antifreeze is a "must have" in an Albertan winter because it helps keep your vehicle engine from freezing in cold temperatures.

Natasha_Volkova [10]

Products such as antifreeze are composed of organic compounds that are classified as <em>alcohols</em>. (a)

Maybe those other classes of chemicals also lower the freezing temperature of water, just like alcohol does. I don't know. But alcohol is what's used to make anti-freeze. I'm guessing alcohol must be cheaper, less toxic, and less corrosive inside the engines' cooling systems than any of that other stuff is.

4 0

3 years ago