All categories

3 years ago

A 15.0-kilogram mass is moving at 7.50 meters per second on a horizontal, frictionless surface. What is the

1 answer:

3 0

The answer is 570 J. The kinetic energy has the formula of 1/2mV². The total work in this process W= 1/2m(V2²-V1²) = 1/2 * 15.0 * (11.5²-7.50²) = 570 J.

You might be interested in

Due to efficiency considerations related to its bow wake, the supersonic transport aircraft must maintain a cruising speed that

givi [52]

Answer:

decreases.

Explanation:

When the aircraft is flies from the warm air into the colder air then its speed will be decreases.

as we know that

we know mach number is constant

so that here Mach number M is expressed as

M = $\frac{u}{v}$ .............................1

here u is Local flow velocity with respect to the boundarie and v is the speed of sound in the medium

If the aircraft flies from hot air to cold air, the speed of sound in the medium will decrease. But the Mach number remains constant. Therefore, the local flow velocity relative to the boundaries also decreases.

7 0

3 years ago

A modern compact fluorescent lamp contains 1.4 mg of mercury (Hg). If each mercury atom in the lamp were to emit a single photon

Reika [66]

Answer:

A. 1.64 J

Explanation:

First of all, we need to find how many moles correspond to 1.4 mg of mercury. We have:

$n=\frac{m}{M_m}$

where

n is the number of moles

m = 1.4 mg = 0.0014 g is the mass of mercury

Mm = 200.6 g/mol is the molar mass of mercury

Substituting, we find

$n=\frac{0.0014 g}{200.6 g/mol}=7.0\cdot 10^{-6} mol$

Now we have to find the number of atoms contained in this sample of mercury, which is given by:

$N=n N_A$

where

n is the number of moles

$N_A=6.022\cdot 10^{23} mol^{-1}$ is the Avogadro number

Substituting,

$N=(7.0\cdot 10^{-6} mol)(6.022\cdot 10^{23} mol^{-1})=4.22\cdot 10^{18}$ atoms

The energy emitted by each atom (the energy of one photon) is

$E_1 = \frac{hc}{\lambda}$

where

h is the Planck constant

c is the speed of light

$\lambda=508 nm=5.08\cdot 10^{-7}nm$ is the wavelength

Substituting,

$E_1 = \frac{(6.63\cdot 10^{-34} Js)(3\cdot 10^8 m/s)}{5.08\cdot 10^{-7} m}=3.92\cdot 10^{-19} J$

And so, the total energy emitted by the sample is

$E=nE_1 = (4.22\cdot 10^{18} )(3.92\cdot 10^{-19}J)=1.64 J$

4 0

3 years ago

BEST ANSWER GET BRAINLEIST!!!!!!!!!!!!!!! PLEASE HELP ASAP!!!!!!!!!!!!!!

ozzi

No person shall be judged by their financial status in the process of applying for a job or position of power in the government.

6 0

3 years ago

Twin brothers, Andy and Brian, can mow their grandparents lawn together in 1212 minutes. Brian would mow the lawn by himself

Karo-lina-s [1.5K]

Answer:

It will take Andy 1.198minutes to mow the lawn and it will take Brian 1,209.98minutes to mow the same lawn.

Step-by-step explanation:

Using the simultaneous equation concept, let A denote Andy and B be Brian

Andy and Brian can mow the lawn for 1212minutes i.e A+B = 1212..eqn 1

If Brian would mow the lawn by himself in 1010 minutes more than it would take Andy, this means B=1010A...eqn 2.

Substituting eqn 2 into eqn 1

Equation 1 becomes

A+1010A=1212

1011A=1212

A=1212/1011

A=1.198

B = 1010×1.198

B=1,209.98

Therefore, It will take Andy 1.198minutes to mow the lawn and it will take Brian 1,209.98minutes to mow the same lawn.

6 0

3 years ago

Which of the following brain imaging techniques produce the most detailed picture of brain structure? (2 points)

Inga [223]

Answer:

MRI

Explanation:

Magnetic Resonance Imaging, furnishes the most detailed picture of brain structure. MRI produces the most point by point picture of the cerebrum. MRI examines by using attractive fields and radio waves to create PC produced pictures that recognize the structures inside the mind. It gives the most point by point and a detailed image of the brain structure.

6 0

3 years ago