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Sophie [7]
3 years ago
7

Lukalu is rappelling off a cliff. The parametric equations that describe her horizontal and vertical position as a function of t

ime are x ( t ) = 8 t and y ( t ) = − 16 t 2 + 100 and . How long does it take her to reach the ground? How far away from the cliff is she when she lands?
Physics
1 answer:
andre [41]3 years ago
4 0

Answer:

2.5 s, 5 m

Explanation:

The equations for the horizontal and vertical position of Lukalu are:

x(t) = 8t\\y(t) = -16t^2 + 100

we can find the time it takes her to reach the ground by requiring that the vertical position becomes zero:

y(t) = 0

So we find:

0=-16t^2 +100\\16t^2 = 100\\t=\sqrt{\frac{100}{16}}=2.5 s

The horizontal distance of Lukalu instead will be given by the equation for the horizontal position, substituting t = 2.5 s:

x=8t = 8 \cdot 2.5 s =5 m

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A person's body is producing energy internally due to metabolic processes. If the body loses more energy than metabolic processe
SVETLANKA909090 [29]

Answer:

T_s = 6.8 degree C

Explanation:

As per thermal radiation we know that rate is heat radiation is given as

\frac{dQ}{dt} = \sigma eA (T^4 - T_s^4)

here we know that

T = 34 degree C = 307 K

A = 1.38 m^2

e = 0.557

\sigma = 5.67 \times 10^{-8} W/m^2K^4

\frac{dQ}{dt} = 120 J/s

now we have

120 = (5.67 \times 10^{-8})(0.557)(1.38)(307^4 - T_s^4)

120 = (4.36 \times 10^{-8})(307^4 - T_s^4)

T_s = 279.8 K

T_s = 6.8 degree C

5 0
3 years ago
Cual sera el caudal que lleva un rio cuando se desplaza a 200 litros cada 40 segundos
alisha [4.7K]

Answer:

Q = 5 L/s

Explanation:

To find the flow you use the following formula (para calcular el caudal usted utiliza la siguiente formula):

Q=\frac{V}{t}

V: Volume (volumen) = 200L

t: time (tiempo) = 40 s

you replace the values of the parameters to calculate Q (usted reemplaza los valores de los parámteros V y t para calcular el caudal):

Q=\frac{200L}{40s}=5\frac{L}{s}

Hence, the flow is 5 L/s (por lo tanto, el caudal es de 5L/s)

4 0
3 years ago
1-A car moves toward east 12km is represented as A and it turns towards south 16km is represented as B. What is the resultant ve
hjlf

1. A-20 km south east

The car's displacement consists of two components into two different directions. Using a system of coordinates in which x represents the east direction and y represents the south direction, the two displacements are:

d_x = 12 km east

d_y = 16 km south

Since the two components are orthogonal to each other, we can find the resultant displacement by using Pythagorean's theorem:

d=\sqrt{d_x^2+d_y^2}=\sqrt{(12 km)^2+(16 km)^2}=\sqrt{400}=20 km

and the direction is between the two original directions, so south-east.

2. D. 10 m/s

First of all, we need to calculate the total time the stone took to hit the ground. Since the vertical distance covered is S = 78.4 m, and since the motion is an accelerated motion with constant acceleration g=9.8 m/s^2, we have

S=\frac{1}{2}gt^2

From which we find the total time of the fall, t:

t=\sqrt{\frac{2S}{g}}=\sqrt{\frac{2(78.4 m)}{9.8 m/s^2}}=4 s

Now we can consider the horizontal motion of the stone: we know that the stone travels for d = 40 m in a time of t = 4 s, therefore the horizontal velocity of the stone is

v=\frac{d}{t}=\frac{40 m}{4 s}=10 m/s

3. B=32.32 m

As in the previous problem, we have to calculate the total time it takes for the stone to reach the river first. Since the vertical distance covered is S = 20 m, we have

t=\sqrt{\frac{2S}{g}}=\sqrt{\frac{2(20 m)}{9.8 m/s^2}}=2.0 s

And since the stone is traveling horizontally at v = 16 m/s, the horizontal distance covered is

d=vt=(16 m/s)(2 s)=32 m

So, the closest answer is B.

5 0
3 years ago
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Marina86 [1]

Answer: Wernicke's Area

Explanation: Wernicke's area is the region of the brain responsible for language <em>interpretation</em>. Broca's area is associated with language <em>production.</em>

6 0
3 years ago
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irinina [24]

Well, that's a nice, concise description, but it applies to a
generator, not a motor.  A motor does exactly the opposite.
It uses an electric current to produce motion in a magnetic field.

Sadly, the statement is false.

5 0
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