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2 years ago

How long will it take a car to speed up from 10m/s to 34m/s if it can accelerate 8m/s/s in the direction it is moving?

Physics

1 answer:

diamong [38]2 years ago

4 0

Answer:

3 s

Explanation:

velocity=initial velocity +a*t

34=10 + 8t

24=8t

t=3 s

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Kyle is flying a helicopter at 125 m/s on a heading of 325 o . If a wind is blowing at 25 m/s toward a direction of 240.0 o , wh

frosja888 [35]

Answer:

The resultant velocity of the helicopter is $\vec v_{H} = \left(89.894\,\frac{m}{s}, -93.348\,\frac{m}{s}\right)$ .

Explanation:

Physically speaking, the resulting velocity of the helicopter ( $\vec v_{H}$ ), measured in meters per second, is equal to the absolute velocity of the wind ( $\vec v_{W}$ ), measured in meters per second, plus the velocity of the helicopter relative to wind ( $\vec v_{H/W}$ ), also call velocity at still air, measured in meters per second. That is:

$\vec v_{H} = \vec v_{W}+\vec v_{H/W}$ (1)

In addition, vectors in rectangular form are defined by the following expression:

$\vec v = \|\vec v\| \cdot (\cos \alpha, \sin \alpha)$ (2)

Where:

$\|\vec v\|$ - Magnitude, measured in meters per second.

$\alpha$ - Direction angle, measured in sexagesimal degrees.

Then, (1) is expanded by applying (2):

$\vec v_{H} = \|\vec v_{W}\| \cdot (\cos \alpha_{W},\sin \alpha_{W}) +\|\vec v_{H/W}\| \cdot (\cos \alpha_{H/W},\sin \alpha_{H/W})$ (3)

$\vec v_{H} = \left(\|\vec v_{W}\|\cdot \cos \alpha_{W}+\|\vec v_{H/W}\|\cdot \cos \alpha_{H/W}, \|\vec v_{W}\|\cdot \sin \alpha_{W}+\|\vec v_{H/W}\|\cdot \sin \alpha_{H/W} \right)$

If we know that $\|\vec v_{W}\| = 25\,\frac{m}{s}$ , $\|\vec v_{H/W}\| = 125\,\frac{m}{s}$ , $\alpha_{W} = 240^{\circ}$ and $\alpha_{H/W} = 325^{\circ}$ , then the resulting velocity of the helicopter is:

$\vec v_{H} = \left(\left(25\,\frac{m}{s} \right)\cdot \cos 240^{\circ}+\left(125\,\frac{m}{s} \right)\cdot \cos 325^{\circ}, \left(25\,\frac{m}{s} \right)\cdot \sin 240^{\circ}+\left(125\,\frac{m}{s} \right)\cdot \sin 325^{\circ}\right)$ $\vec v_{H} = \left(89.894\,\frac{m}{s}, -93.348\,\frac{m}{s}\right)$

The resultant velocity of the helicopter is $\vec v_{H} = \left(89.894\,\frac{m}{s}, -93.348\,\frac{m}{s}\right)$ .

8 0

2 years ago

The cunninghams are moving across the country. Mr.cunningham leaves 2.5 hours before mrs.cunningham. If he averages 40 mph and s

Eva8 [605]

When she starts out, he is (40x2.5)= 100 miles ahead of her.

She gains (65-40)= 25 miles on him every hour.

It takes her (100/25)= 4 hours to catch up to him.

5 0

2 years ago

What is the lowest gauge pressure that the average person can achieve inside his lungs? express your answer with the appropriate

eimsori [14]

<span>9000 Pascals Looking on the internet, it appears that a human can only suck about 3 feet of water. So let's convert that measurement into a few more convenient units. cmH2O = 36 * 2.54 = 91.44 cmH2O cmHg = 91.44 * 0.73555912101486 = 67.26 mmHg Pascal = 91.44 * 98.0665 = 8967 Pascals PSI = 91.44 * 0.0142233 = 1.3 psi Since we're dealing with science and the metric system is the most common system used in science, I'd recommend an answer of 9000 Pascals.</span>

4 0

3 years ago

What is the resistance in a circuit that is connected to a 20 V battery and has a

Amanda [17]

Answer:

$R = \displaystyle\frac{V}{I}$

$R = \displaystyle\frac{20}{75}$

$R = 0.267$ Ω (approx)

7 0

2 years ago

How is the direction of a vector affected when it is multiplied by a scalar?

pantera1 [17]

The direction of a vector multiplied by a scalar is only affected if the scalar is negative, in which case the vector will now be in the opposite direction. If the scalar is positive, the vector will only change in magnitude

6 0

2 years ago