A _____ resource could run out thousands of years from now.

A 25 Kg rock is sitting on a cliff that is 50 meters above the ground. If it fell off of the cliff, and all energy was conserved

svetlana [45]

Answer:

v = 31.32 [m/s]

Explanation:

To solve this problem we must use the principle of energy conservation, which tells us that potential energy is converted into kinetic energy or vice versa. The potential energy can be calculated by the product of mass by gravity by height.

$E_{pot}=m*g*h$

where:

Epot = potential energy [J]

m = mass = 25 [kg]

g = gravity acceleration = 9.81 [m/s²]

h = elevation = 50 [m]

Now replacing:

$E_{pot}=25*9.81*50\\E_{pot}= 12262.5[J]$

When the rock falls the potential energy is converted into kinetic energy.

$E_{pot}=E_{k}\\E_{k}=\frac{1}{2}*m*v^{2}$

where:

Ek = kinetic energy [J]

v = velocity [m/s]

Now clearing v:

$v^{2} =\frac{E_{k}*2}{m}\\v=\sqrt{(2*12262)/25}\\v = 31.32 [m/s]$

8 0

3 years ago

How do its eight arms help an octopus obtain food

Andrews [41]

The more arms it has the less of a chance the prey has to swim away.

5 0

3 years ago

a 91.5 kg football player running east at 3.73 m/s tackles a 63.5 kg player running east at 3.09 m/s. what is their velocity aft

Lesechka [4]

The final velocity is 3.47 m/s east

Explanation:

We can solve this problem by using the law of conservation of momentum. In fact, the total momentum of the two players before and after the collision must be conserved:

$p_i = p_f\\m_1 u_1 + m_2 u_2 = (m_1+m_2)v$