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4 years ago

If we have a velocity of 20 m/s and our acceleration is -5 m/s, then after 2 seconds our velocity will be....

Physics

1 answer:

svetoff [14.1K]4 years ago

6 0

Answer:

v = 10 m/s

Explanation:

We have,

Our initial velocity is 20 m/s

Our acceleration, $a=-5\ m/s^2$

It is required to find the velocity after 2 seconds. It is a concept based on equation of kinematics. Using first equation:

$v=u+at$

Plugging all the known values

$v=20+(-5)(2)\\\\v=10\ m/s$

So, our final velocity is 10 m/s.

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Occasionally, people can survive falling large distances if the surface they land on is soft enough. During a traverse of Eiger'

uranmaximum [27]

Answer:

4611.58 ft/s²

Explanation:

t = Time taken

u = Initial velocity

v = Final velocity

s = Displacement

a = Acceleration due to gravity = 32.174 ft/s²

Equation of motion

$v^2-u^2=2as\\\Rightarrow v=\sqrt{2as+u^2}\\\Rightarrow v=\sqrt{2\times 32.174\times 516+0^2}\\\Rightarrow v=182.218\ ft/s$

$v^2-u^2=2as\\\Rightarrow a=\frac{v^2-u^2}{2s}\\\Rightarrow a=\frac{0^2-182.218^2}{2\times 3.6}\\\Rightarrow a=-4611.58\ ft/s^2$

Magnitude of acceleration while stopping is 4611.58 ft/s²

8 0

3 years ago

What is the pressure drop due to the Bernoulli Effect as water goes into a 3.00-cm-diameter nozzle from a 9.00-cm-diameter fire

Marianna [84]

Answer:

The pressure and maximum height are $1.58\times10^{6}\ N/m^2$ and 161.22 m respectively.

Explanation:

Given that,

Diameter = 3.00 cm

Exit diameter = 9.00 cm

Flow = 40.0 L/s²

We need to calculate the pressure

Using Bernoulli effect

$P_{1}+\dfrac{1}{2}\rho v_{1}^2+\rho g h_{1}=P_{2}+\dfrac{1}{2}\rho v_{2}^2+\rho g h_{2}$

When two point are at same height so ,

$P_{1}+\dfrac{1}{2}\rho v_{1}^2=P_{2}+\dfrac{1}{2}\rho v_{2}^2$ ....(I)

Firstly we need to calculate the velocity

Using continuity equation

For input velocity,

$Q=A_{1}v_{1}$

$v_{1}=\dfrac{Q}{A_{1}}$

$v_{1}=\dfrac{40.0\times10^{-3}}{\pi\times(1.5\times10^{-2})^2}$

$v_{1}=56.58\ m/s$

For output velocity,

$v_{2}=\dfrac{40.0\times10^{-3}}{\pi\times(4.5\times10^{-2})^2}$

$v_{2}=6.28\ m/s$

Put the value into the formula

$P_{1}-P_{2}=\dfrac{1}{2}\rho(v_{1}^2-v_{2}^2)$

$\Delta P=\dfrac{1}{2}\times1000\times(56.58^2-6.28^2)$

$\Delta P=1.58\times10^{6}\ N/m^2$

(b). We need to calculate the maximum height

Using formula of height

$\Delta P=\rho g h$

Put the value into the formula

$1.58\times10^{6}=1000\times9.8\times h$

$h=\dfrac{1.58\times10^{6}}{1000\times9.8}$

$h=161.22\ m$

Hence, The pressure and maximum height are $1.58\times10^{6}\ N/m^2$ and 161.22 m respectively.

8 0

3 years ago

Stella has poured 3 cups of water into a 1-L soda bottle. Stella then sealed the bottle and placed it in the sunlight. What natu

KonstantinChe [14]

<span>Answer is: A. water cycle.
Under influence of sunlight (energy), water evaporates (liquid phase transform into gas phase). Gas, after contact with bottle, turns into liquid phase again (condensation). That is happening with water in nature also (</span><span>water moves from one reservoir to another).</span>

3 0

3 years ago

A sound signal traveling underwater has a frequency of 230 hertz. The speed of sound under water is 1. 45 × 103 meters/second. W

nirvana33 [79]

Answer:

A.6.3

Explanation:

4 0

3 years ago

The liquid in the cup is brown" is an example of an ..............

erastova [34]

Eaither D or A bit I am leaning more towards D