Please tell me the order the answers go. Best and most correct answer gets Brainliest.

A weightlifter works out at the gym each day. Part of her routine is to lie on her back and lift a 43 kg barbell straight up fro

Tasya [4]

Answer:

A. 231.77 J

B. 5330.71 J

C. 46 donuts

Explanation:

A. To lift the barbell once, she will have to extend it the full length of her arm. The work done will then be:

W = F * d

Where the force is the weight of the barbell.

F = m * g

Hence, the work done in lifting the barbell is:

W = m * g * d

W = 43 * 9.8 * 0.55

W = 231.77 J

B. If she does 23 repetitions, the total energy she expend will be equal to the Potential energy when the barbell is lifted multiplied by 23:

E = 23 * m * g * d

E = 23 * 231.77

E = 5330.71 J

C. 1 Joule = 4.184 calories

5330.71 Joules = 5330.71 * 4.184 = 22303.69

If 1 donut contains 490 calories, the number of donuts she will need will be:

N = 22303.69/490 = 45.5 donuts or 46 donuts

5 0

3 years ago

How did people manage to survive and thrive tens of thousands of years ago?

Debora [2.8K]

Answer: During medieval times, men, especially outlaws, would keep warm in the winter by wearing a linen shirt with underclothes, mittens made of wool or leather and woolen coats with a hood over a tight cap called a coif.

Explanation:

HOPE THAT HELPED A LITTLE

8 0

3 years ago

Read 2 more answers

Consider an electron with charge −e and mass m orbiting in a circle around a hydrogen nucleus (a single proton) with charge +e.

alexandr1967 [171]

Answer:

$v=\sqrt{k\frac{e^2}{m_e r}}$ , $2.18\cdot 10^6 m/s$

Explanation:

The magnitude of the electromagnetic force between the electron and the proton in the nucleus is equal to the centripetal force:

$k\frac{(e)(e)}{r^2}=m_e \frac{v^2}{r}$

where

k is the Coulomb constant

e is the magnitude of the charge of the electron

e is the magnitude of the charge of the proton in the nucleus

r is the distance between the electron and the nucleus

v is the speed of the electron

$m_e$ is the mass of the electron

Solving for v, we find

$v=\sqrt{k\frac{e^2}{m_e r}}$

Inside an atom of hydrogen, the distance between the electron and the nucleus is approximately

$r=5.3\cdot 10^{-11}m$

while the electron mass is

$m_e = 9.11\cdot 10^{-31}kg$

and the charge is

$e=1.6\cdot 10^{-19} C$

Substituting into the formula, we find

$v=\sqrt{(9\cdot 10^9 m/s) \frac{(1.6\cdot 10^{-19} C)^2}{(9.11\cdot 10^{-31} kg)(5.3\cdot 10^{-11} m)}}=2.18\cdot 10^6 m/s$

7 0

3 years ago

Which statement about gravity is true?

SVETLANKA909090 [29]

Out of the given options, ‘it is described as a fundamental force and therefore does not depend on other forces’ is the true statement about gravity.

Answer: Option B

<u>Explanation: </u>

As we all know that there are four fundamental forces existing in the universe- Electromagnetic force, strong forces, weak forces and the gravitational force.

These are the forces that don’t depend on any other physical force to draw a considerable impact on the physical objects. The gravitational force can be defined as,

$F=G \times \frac{m_{1} m_{2}}{r^{2}}$

Where,

G = Gravitational Constant

$m_{1} , m_{2}$ = Masses of two substances under consideration

R = distance between the two substances.

Looking upon the formula of gravitational force we can easily estimate that the gravitational force relies on the mass of substances and the relative distance between them. There is no factor than the air friction that hinders the gravitational force and that too in a negligible amount.

5 0

3 years ago

A "spherical capacitor" is constructed of two thin, concentric spherical shells of conducting material. Let a be the radius of t

Shalnov [3]

Answer:

$C=\frac{ab}{k(b-a)}$