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3 years ago

Jumps at 8 m/s at a 30 degree angle above the horizontal. how long was she in the air?

1 answer:

4 0

Vo = 8 m/s. g = 10 m/s^2
alpha = 30 degree
ask: x?

x = vo^2 sin ^2 alpha / g
x = 8 ^2 x 2 sin 30 cos 30 / 10
x =( 64 x2x 1/2x1/2√3 )/ 10
x= 3.2 √3 metres

√3 = 1.73

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The current theory of the structure of the

IRISSAK [1]

1) The mass of the continent is $3.3\cdot 10^{21} kg$

2) The kinetic energy of the continent is 624 J

3) The speed of the jogger must be 4 m/s

Explanation:

We start by finding the volume of the continent. We have:

$L = 5850 km = 5.85\cdot 10^6 m$ is the side

$t = 35 km = 3.5\cdot 10^4 m$ is the depth

So the volume is

$V=L^2 t = (5.85\cdot 10^6)^2 (3.5\cdot 10^4)=1.20\cdot 10^{18} m^3$

We also know that its density is

$d=2750 kg/m^3$

Therefore, we can find the mass by multiplying volume by density:

$m=dV=(2750)(1.20\cdot 10^{18})=3.3\cdot 10^{21} kg$

The kinetic energy of the continent is given by:

$K=\frac{1}{2}mv^2$

where

$m=3.3\cdot 10^{21} kg$ is its mass

v = 3.2 cm/year is the speed

We have to convert the speed into m/s. We have:

3.2 cm = 0.032 m

$1 year = 1(365)(24)(60)(60)=3.15\cdot 10^7 s$

So, the speed is:

$v=\frac{0.032 m}{3.15 \cdot 10^7 s}=1.02\cdot 10^{-9} m/s$

So, we can now find the kinetic energy:

$K=\frac{1}{2}(1.20\cdot 10^{21})(1.02\cdot 10^{-9})^2=624 J$

Here we have a jogger of mass

m = 78 kg

And the jogger has the same kinetic energy of the continent, so

K = 624 J

The kinetic energy of the jogger is given by

$K=\frac{1}{2}mv^2$

where v is the speed of the jogger.

Solving for v, we find the speed that the jogger must have:

$v=\sqrt{\frac{2K}{m}}=\sqrt{\frac{2(624)}{78}}=4 m/s$

Learn more about kinetic energy:

brainly.com/question/6536722

#LearnwithBrainly

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3 years ago

List three sources of information scientists use to learn about ancient climates

blagie [28]

Rocks,Fossils,Carbon dating

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3 years ago

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A satellite camera in space took this picture of northwestern Algeria, showing an impact crater, sedimentary

Mars2501 [29]

Simple the answer is D

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2 years ago

What is the kinetic energy of a 1.00g hailstone falling at 8.50m/s

bearhunter [10]

Answer:

36.125 J

Explanation:

The formula for kinetic energy is KE = .5(m)(v²).

Using the given information, mass = 1 g and v = 8.50. Plug that information into the equation. KE = .5(1)(8.50²) = 36.125 J.

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3 years ago

A physics professor is pushed up a ramp inclined upward at an angle 33.0Â° above the horizontal as he sits in his desk chair tha

Andru [333]

Answer:

2.51 m/s

Explanation:

Parameters given:

Angle, A = 33°

Mass, m = 90kg

Inclined distance, D = 2m

Force, F = 600N

Initial speed, u = 2.3m/s

From the relationship between work and kinetic energy, we know that:

Work done = change in kinetic energy

W = 0.5m(v² - u²)

We also know that work done is tẹ product of force and distance, hence, net work done will be the sum of the total work done by the force from the students and gravity.

Hence,

W = F*D*cosA - w*D*sinA

w = m*9.8 = weight

=> W = 600*2*cos33 - 90*9.8*2*sin33

W = 45.7J

=> 45.7 = 0.5*m*(v² - u²)

45.7 = 0.5*90*(v² - 2.3²)

45.7 = 45(v² - 5.29)

=> v² - 5.29 = 1.016

v² = 6.306

v = 2.51 m/s

The final velocity is 2.51 m/s

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3 years ago

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