(this is a practice not a test) I'm struggling to find the answers to this question, could you guys help me?

Find the hiker’s gravitational potential energy if the cliff is 60m high

Furkat [3]

Answer:

Potential energy is $U=mgh$

Explanation:

The potential energy depends on the mass, the acceleration of gravity g and the height at which the object or person is.

Potential energy $U=mgh$

In this case we would need to know the exact mass of the hiker in order to calculate the potential energy.

But we know the values of g and h

$g=9.81m/s^2$

$h=60m$

So, the potential energy

$U=m(9.81m/s^2)(60m)\\\\U=588.6*m$

m is the mass of the hiker, wich is not in the description of the problem.

4 0

3 years ago

Which element has 7 valence electrons?

wlad13 [49]

the element has 7 valance electrons is CI:Chlorine

7 0

3 years ago

The energies of electrons are said to be quantized. Explain what this means. please explain.

sleet_krkn [62]

To move from one energy level to another, an electron must gain or lose just the right amount of energy. Electrons are said to be quantized because they need a quantum of energy to move to a different sublevel. ... When atoms absorb energy, electrons move into higher energy levels.

8 0

3 years ago

A water balloon is hovering directly above the line join points ANB which are 4.6 km apart if the angles of elevation to the bal

Anna35 [415]

Answer:

Drawing the triangle:

H / x = tan 52.2 = 1.29

H / (4.6 - x) = tan 28.8 = .550

H = 1.29 x

H = .55 * 4.6 - .55 x

1.84 x = 2.53 combining equations

x = 1.38

4.6 - 1.38 = 3.22

Total base of triangle = 1.38 + 3.22 = 4.6

H / x = tan 52,2 = 1.29

H = 1.29 * 1.38 = 1.78 height of triangle

Check:

1.78 / 3.22 = tan 28.9

This agrees with the given value of 28.8

7 0

2 years ago

n 38 g rifle bullet traveling at 410 m/s buries itself in a 4.2 kg pendulum hanging on a 2.8 m long string, which makes the pend

Kitty [74]

Answer:

68cm

Explanation:

You can solve this problem by using the momentum conservation and energy conservation. By using the conservation of the momentum you get

$p_f=p_i\\mv_1+Mv_2=(m+M)v$

m: mass of the bullet

M: mass of the pendulum

v1: velocity of the bullet = 410m/s

v2: velocity of the pendulum =0m/s

v: velocity of both bullet ad pendulum joint

By replacing you can find v:

$(0.038kg)(410m/s)+0=(0.038kg+4.2kg)v\\\\v=3.67\frac{m}{s}$

this value of v is used as the velocity of the total kinetic energy of the block of pendulum and bullet. This energy equals the potential energy for the maximum height reached by the block:

$E_{fp}=E_{ki}\\\\(m+M)gh=\frac{1}{2}mv^2$

g: 9.8/s^2

h: height

By doing h the subject of the equation and replacing you obtain:

$(0.038kg+4.2kg)(9.8m/s^2)h=\frac{1}{2}(0.038kg+4.2kg)(3.67m/s)^2\\\\h=0.68m$

hence, the heigth is 68cm

4 0

3 years ago

(this is a practice not a test) I'm struggling to find the answers to this question, could you guys help me?​

(this is a practice not a test) I'm struggling to find the answers to this question, could you guys help me?