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sasho [114]
2 years ago
9

1. Do alto de uma plataforma com 15m de altura, é lançado horizontalmente um projéctil. Pretende-se atingir um alvo localizado n

o solo, a 50m da vertical, que contém o ponto de lançamento.
a) Determine a velocidade inicial do lançamento;
b) Determine a velociade ao tocar o solo.
Physics
1 answer:
sveta [45]2 years ago
4 0

Answer:

(a). The initial velocity is 28.58m/s

(b). The speed when touching the ground is 33.3m/s.

Explanation:

The equations governing the position of the projectile are

(1).\: x =v_0t

(2).\: y= 15m-\dfrac{1}{2}gt^2

where v_0 is the initial velocity.

(a).

When the projectile hits the 50m mark, y=0; therefore,

0=15-\dfrac{1}{2}gt^2

solving for t we get:

t= 1.75s.

Thus, the projectile must hit the 50m mark in 1.75s, and this condition demands from equation (1) that

50m = v_0(1.75s)

which gives

\boxed{v_0 = 28.58m/s.}

(b).

The horizontal velocity remains unchanged just before the projectile touches the ground because gravity acts only along the vertical direction; therefore,

v_x = 28.58m/s.

the vertical component of the velocity is

v_y = gt \\v_y = (9.8m/s^2)(1.75s)\\\\{v_y = 17.15m/s.

which gives a speed v of

v = \sqrt{v_x^2+v_y^2}

\boxed{v =33.3m/s.}

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  • The wavelength of the red light in "nanometer" is 7× 10^{2}

  • Wavelength is given as : 7×10^{-7} meter

  • 1 nanometer = (10^{-9} meter)

  • Let X= value of the wavelength in nanometer.

1 nanometer  = 10^{-9} meter

X nanometer = 7× 10^{-7}  meter

  • <em>If we Cross multiply</em>

X nanometer = (\frac{     7* 10^{-7} }{  10^{-9} })

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2 years ago
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gulaghasi [49]

Answer:

The current across the resistance is 0.011 A.

Explanation:

Total resistance, R = 25 ohms

Total current, I = 100 mA = 0.1 A

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By the Ohm's law

V = I R

V = 0.1 x 25 = 2.5 V

Now the resistance is R' = 220 ohm

As they are in parallel so the voltage is same. Let the current is I'.

V = I' x R'

2.5 = I' x 220

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A 60 kg runner accelerates during a race at 3m/s2. what force is exerted on the earth with each step
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180 Newton(N)

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One of the longer sides of a kite is 39 feet. one of the shorter sides is 25 feet. half the length of the shorter diagonal is 15
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It would point up.

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Since the compass is free to swivel in any direction, the compass would point up, since it is at the earth's geographic north magnetic pole, the place on the earth's surface that compasses point toward.

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