If you hold a 50 kilogram barbell above your head for 3 seconds and

If a 80kg diver jumps off of a 5 m high dive into a regulation diving pool, how much should the temperature of the pool go up?

Agata [3.3K]

Answer:

The answer cannot be determined.

Explanation:

The energy of the diver when he hits the pool will be equal to its potential energy $mgh$ , and for the temperature of the pool to rise up, this energy has to be converted into the heat energy of the pool.

The change in temperature ${\Delta}T$ then will be

${\Delta}T=\frac{{\Delta}Q}{mc} .$

Where m is the mass of water in the pool, c is the specific heat capacity of water, and ${\Delta}Q$ is the added heat which in this case is the energy of the diver.

Since we do not know the mass of the water in the pool, we cannot make this calculation.

7 0

3 years ago

Sally takes two bar magnets and randomly tapes one end of each bar magnet. she labels the magnets A and B. She brings the taped

Artyom0805 [142]

I already answered this quesiton. The fact is that there are only two kind of poles and since the two taped poles of the magnets labeled A and B attracts one to each other, we know that the two taped poles of the first two magnets are oppsosite.

Then, the taped pole of the third magnet has to be equal to one of the first two taped poles and opposite to the other of the first two taped poles.

That drives you to conclude (predict) that when she brings the taped end of the third magnet (magnet C) near each of the first two magntes, in one case they will attract each other and in the other case they will repele mutually.

4 0

3 years ago

calculate the work done in kilo joules in lifting a mass of 20kg at steady velocity through a vertical height of 20m

bulgar [2K]

Answer:

$\huge\boxed{\sf Work\ done = 4 kJ}$

Explanation:

Since work done is in the form of potential energy, we will use the formula of potential energy here.

We know that,

Where,

m = mass = 20 kg

g = acceleration due to gravity = 10 m/s²

h = vertical height = 20 m

So,

Work done = (20)(10)(20)

Work done = 4000 joules

Work done = 4 kJ

$\rule[225]{225}{2}$

5 0

2 years ago

In a simplified model of a hydrogen atom, the electron moves around the proton nucleus in a circular orbit of radius 0.53×10−10m

Ksenya-84 [330]

Answer

given,

radius of the circular orbit, r = 0.53 x 10⁻¹⁰ m

mass of electron, M = 9.11 x 10⁻³¹ Kg

charge of electron, q₁ = 1.6 x 10⁻¹⁹ C

q₂ = 1.6 x 10⁻¹⁹ C

we know, force between two charges

$F = \dfrac{kq_1q_2}{r^2}$

$F = \dfrac{9\times 10^9\times (1.6\times 10^{-19})^2}{(0.53\times 10^{-10})^2}$

F = 8.20 x 10⁻⁸ N

b) using newton's second law

F = m a

m a = 8.20 x 10⁻⁸

$a =\dfrac{8.20\times 10^{-8}}{9.11\times 10^{-31}}$

a = 9 x 10²² m/s²

c) speed of the electron

$a =\dfrac{v^2}{r}$

$9\times 10^{22} =\dfrac{v^2}{0.53\times 10^{-10}}$

v² = 4.77 x 10¹²

v = 2.18 x 10⁶ m/s

d) the period of the circular motion.

$T=\dfrac{2\pi}{\omega}$

$T=\dfrac{2\pi r}{v}$

$T=\dfrac{2\pi\times 0.53\times 10^{-10}}{2.18\times 10^6}$

T = 1.53 x 10⁻¹⁶ s

8 0

3 years ago

Read 2 more answers

Two cylindrical containers are placed on a turntable. canister A is empty; canister B contains lead shots. each canister is the

devlian [24]

Answer:

c) both containers slide off the turntable at the same turntable speed.

Explanation:

The greater the mass of the cylinder, the greater the centrifugal force acting on it. That makes up for the greater force needed to move the heavier cylinder.

5 0

3 years ago