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2 years ago

6

If the ball reaches the ground in 8 seconds and the velocity of the ball before it hits the ground is 78.4. What is its accelera

tion?
also please explain how if you can

1 answer:

Natasha2012 [34]2 years ago

6 0

Answer:

9.8 m / s^2

Explanation:

Assuming free fall====> there is no initial downward/upward velocity

Assuming metric units 78.4<u> m/s </u>

vf = a t

78.4 = a (8) shows a = 9.8 m/s^2

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The area of the tympanic membrane is 100 mm 2 and the area of the oval window is 5 mm 2 . if a sound wave applies 10 n to the ty

Flura [38]

<span>The answer is "0.5N".

According to the question;
P1=P2
so,
F1/A1= F2/A2

P=(F/A)

A1=100mm</span>²
<span>
F1= 10N

A2= 5mm</span>²
<span>
F2= ?

F2= ((F1 x A2)/A1)
= ((10 x 5) /100)

=50/100

=0.5N</span>

8 0

3 years ago

A pulsar is a rapidly rotating neutron star that emits a radio beam the way a lighthouse emits a light beam. We receive a radio

Gnesinka [82]

Answer:

a). $a_p=-2.39x10^{-12} rad/s^2$

b). $t=1016298.8 years$

c). $T_i=80.58x10^{-3}s$

Explanation:

a).

The acceleration for definition is the derive of the velocity so:

$a_p=\frac{dw}{dt}$

$w=\frac{2\pi}{t}$

$a_p=\frac{dw}{dt}=-\frac{2\pi}{t^2}*\frac{dT}{dt}$

$dT=0.0808s$

$dt=1 year*\frac{365d}{1year} \frac{24hr}{1d} \frac{60minute}{1hr} \frac{60s}{1minute}=31.536x10^{6}s$

Replacing

$a_p=-\frac{2\pi}{0.082s^2}*\frac{9.84x10^{-7}}{31.536x10^{6}s}= -2.39x10^{-12} rad/s^2$

b).

If the pulsar will continue to decelerate at this rate, it will stop rotating at time:

$t=\frac{w}{a_p}$

$w=\frac{2\pi }{t}=\frac{2\pi }{0.0820s}=76.62 rad/s$

$t=\frac{76.62 rad/s}{2.39x10^{-12}rad/s^2}= 3.2058x10^{13}s$

$t=1016298.8 years$

c).

582 years ago to 2019

1437

$T_i=0.0820-9.84x10^{-7}*1437)=80.58x10^{-3}s$

5 0

3 years ago

Height of a low earth orbit?

Darya [45]

I used google but 2000km

7 0

3 years ago

Read 2 more answers

A storage tank holds methane at 120 K, with a quality of 25 %, and it warms up by 5°C per hour due to a failure in the refrigera

lord [1]

One of the fundamental pillars to solve this problem is the use of thermodynamic tables to be able to find the values of the specific volume of saturated liquid and evaporation. We will be guided by the table B.7.1 'Saturated Methane' from which we will obtain the properties of this gas at the given temperature. Later considering the isobaric process we will calculate with that volume the properties in state two. Finally we will calculate the times through the differences of the temperatures and reasons of change of heat.

Table B.7.1: Saturated Methane

$T_1 = 120K$

$p_1 = 191.6kPa$

$v_f = 0.002439m^3/kg$

$v_{fg} = 0.30367 m^3/kg$

Calculate the specific volume of the methane at state 1

$v_1 = v_f+x_1v_{fg}$

$v_1 = 0.002439+ (0.25)(0.30367)$

$v_1 = 0.0783m^3/kg$

Assume the tank is rigid, specific volume remains constant

$v_2 = v_1$

$v_2 = 0.0783m^3/kg$

Now from the same table we can obtain the properties,

At $v_g = 0.0783m^3/kg$

$T_2 = 145K$

$p_2 = 823.7kPa$

We can calculate the time taken for the methane to become a single phase

$t = \frac{T_2-T_1}{\dot{T}}$

Here

$T_1 =$ Initial temperature of Methane

$\dot{T} =$ Warming rate

Replacing

$t = \frac{(145-273)-(120-273)}{5}$

$t = \frac{25}{5}$

$t = 5hr$

Therefore the time taken for the methane to become a single phase is 5hr

5 0

3 years ago

Derive an expression to show tha v=✓2Gr

Elza [17]

Answer:

From this equation, it can be said that the escape velocity depends on the radius of the planet and the mass of the planet only and not on the mass of the body. Escape Velocity of Earth= 11.2 km/s. This was the derivation of the escape velocity of earth or any other planet.

Explanation:

8 0

2 years ago