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3 years ago

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An 85-kg rock climber, when reaching the summit, built up 250,000 J of gravitational potential energy. How high did the climber

go?

2 answers:

Elodia [21]3 years ago

4 0

Answer: 300 m

Explanation:

A body possesses gravitational potential energy due to virtue of its height above the surface. It is measured in Joules. it is given by:

G.P.E = m g h

where, m is the mass, g is the acceleration due to gravity and h is the height.

Given: m = 85 kg

G.P.E = 250,000 J

g = 9.8 m/s²

⇒ h = (G.P.E}/ mg

⇒h = (250,000) / ( 85 × 9.8) = 300 m.

The climber climbed 300 m high.

Vesna [10]3 years ago

3 0

It's 300! I just got it correct:)

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A father racing his son has 1/3 the kinetic energy of the son, who has 1/4 the mass of the father. The father speeds up by 1.5 m

Feliz [49]

Explanation:

Let the speeds of father and son are $v_f\ and\ v_s$ . The kinetic energies of father and son are $K_f\ and\ K_s$ . The mass of father and son are $m_f\ and\ m_s$

(a) According to given conditions, $K_f=\dfrac{1}{3}K_s$

And $m_s=\dfrac{1}{4}m_f$

Kinetic energy of father is given by :

$K_f=\dfrac{1}{2}m_fv_f^2$ .............(1)

Kinetic energy of son is given by :

$K_s=\dfrac{1}{2}m_sv_s^2$ ...........(2)

From equation (1), (2) we get :

$\dfrac{v_f^2}{v_s^2}=\dfrac{1}{12}$ ..............(3)

If the speed of father is speed up by 1.5 m/s, so the ratio of kinetic energies is given by :

$\dfrac{K_f}{K_s}=\dfrac{1/2m_f(v_f+1.5)^2}{1/2m_sv_s^2}$

$v_s^2=4(v_f+1.5)^2$

Using equation (3) in above equation, we get :

$v_f=\dfrac{1.5}{\sqrt3-1}=2.04\ m/s$

(b) Put the value of $v_f$ in equation (3) as :

$v_s=7.09\ m/s$

Hence, this is the required solution.

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4 years ago

planet a has twice the mass of planet b. from this info what can we conclude about the acceleration due to gravity at the surfac

tangare [24]

Answer: acceleration due to gravity of planet a would be twice that of planet b. Given that the radius are thesame.

Explanation:

Acceleration due to gravity is as a result of the gravitational force of attraction of a planet to its centre.

g = GM/r^2

Where;

g = acceleration due to gravity

G = gravitational constant

M = mass of planet

r = radius of planet

Given that the two planet have the same radius, if the mass of planet a is twice the mass of planet b the the acceleration due to gravity of planet a would be twice that of planet b, because acceleration due to gravity is directly proportional to the mass of the planet.

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3 years ago

A jet airliner moving initially at 406 mph (with respect to the ground) to the east moves into a region where the wind is blowin

astraxan [27]

Answer:

966 mph

Explanation:

Using as convention:

- East --> positive x-direction

- North --> Positive y-direction

The x- and y- components of the initial velocity of the jet can be written as

$v_{1x} = 406 mph\\v_{1y} = 0$

While the components of the velocity of the wind are

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So the components of the resultant velocity of the jet are

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Strike441 [17]

Answer:

This question can be answered by using conversation of energy.

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Explanation:

Note that we take $K_2 = 0$ because we are looking for the minimum initial speed for the penguin to reach the top of the second hill. Any other speed more than this will already be enough for him.

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pantera1 [17]

answer

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Explanation:

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