answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
IRINA_888 [86]
2 years ago
5

A millionairess was told in 1992 that she had exactly 15 years to live. However, if she immediately takes off, travels away from

the Earth at 0.8 c and then returns at the same speed, the last New Year's Day the doctors expect her to celebrate is:
Physics
1 answer:
mamaluj [8]2 years ago
7 0

Answer:

The expected year is 2017.

Explanation:

Total years that the millionaire to live = 15 years

Travel away from the earth at  = 0.8 c

This is a time dilation problem so if she travels at 0.8 c then her time will pass at slower. Below is the following calculation:

T = \frac{T_o}{ \sqrt{1-\frac{V^2}{c^2}}} \\T = \frac{15}{ \sqrt{1-\frac{0.8^2}{c^2}}} \\T = 25 years

Thus the doctors are expecting to celebrate in the year, 1992 + 25 = 2017

You might be interested in
Two identical horizontal sheets of glass have a thin film of air of thickness t between them. The glass has refractive index 1.4
Gre4nikov [31]

Answer:

the wavelength λ of the light when it is traveling in air = 560 nm

the smallest thickness t of the air film = 140 nm

Explanation:

From the question; the path difference is Δx = 2t  (since the condition of the phase difference in the maxima and minima gets interchanged)

Now for constructive interference;

Δx= (m+ \frac{1}{2} \lambda)

replacing ;

Δx = 2t   ; we have:

2t = (m+ \frac{1}{2} \lambda)

Given that thickness t = 700 nm

Then

2× 700 = (m+ \frac{1}{2} \lambda)     --- equation (1)

For thickness t = 980 nm that is next to constructive interference

2× 980 = (m+ \frac{1}{2} \lambda)     ----- equation (2)

Equating the difference of equation (2) and equation (1); we have:'

λ = (2 × 980) - ( 2× 700 )

λ = 1960 - 1400

λ = 560 nm

Thus;  the wavelength λ of the light when it is traveling in air = 560 nm

b)  

For the smallest thickness t_{min} ; \ \ \ m =0

∴ 2t_{min} =\frac{\lambda}{2}

t_{min} =\frac{\lambda}{4}

t_{min} =\frac{560}{4}

t_{min} =140 \ \  nm

Thus, the smallest thickness t of the air film = 140 nm

7 0
2 years ago
Read 2 more answers
The force shown in the attached figure is the net eastward force acting on a ball. The force starts rising at t = 0.012 s, falls
kifflom [539]
Impulse = Integral of F(t) dt from 0.012s to 0.062 s

Given that you do not know the function F(t) you have to make an approximation.

The integral is the area under the curve.

The problem suggest you to approximate the area to a triangle.

In this triangle the base is the time: 0.062 s - 0.012 s = 0.050 s

The height is the peak force: 35 N.

Then, the area is [1/2] (0.05s) (35N) = 0.875 N*s

Answer> 0.875 N*s
6 0
2 years ago
Oceanographers use submerged sonar systems, towed by a cable from a ship, to map the ocean floor. In addition to their downward
KATRIN_1 [288]

Answer:

Tension in the cable is T = 16653.32 N

Explanation:

Give data:

Cross section Area A = 1.3 m^2

Drag coefficient CD = 1.2

Velocity V = 4.3 m/s

Angle made by cable with horizontal  =30 degree

Density \rho \ of\  water= 1000 kg/m3

 Drag force FD is given as

F_{D} = \fracP{1}{2} \rho v^{2} C_{D} A

        = 0.5\times 1000\times 4.32\times  1.2\times 1.3

Drag force = 14422.2 N acting opposite to the motion

As cable made angle  of 30 degree with horizontal  thus horizontal component is take into action to calculate drag force

TCos30 = F_D

T = \frac{F_D}{cos30}

T =\frac{ 14422.2}{cos 30}

T = 16653.32 N

7 0
2 years ago
James Joule (after whom the unit of energy is named) claimed that the water at the bottom of Niagara Falls should be warmer than
Molodets [167]

Answer:

0.12 K

Explanation:

height, h = 51 m

let the mass of water is m.

Specific heat of water, c = 4190 J/kg K

According to the transformation of energy

Potential energy of water = thermal energy of water

m x g x h = m x c x ΔT

Where, ΔT is the rise in temperature

g x h =  c x ΔT

9.8 x 51 = 4190 x ΔT

ΔT = 0.12 K

Thus, the rise in temperature is 0.12 K.

7 0
2 years ago
A bicyclist travels the first 800 m of a trip 1.4 minutes, the next 500 m in 1.6 minutes, and finishes up the final 1200 m in 2
soldier1979 [14.2K]

Answer:

 v_average = 500 m / min

Explanation:

Average speed is defined

         v = (x_{f} -x₀) / Δt

let's look in each section

section 1

the variation of the distance is 800 in a time of 1.4 min

         v₁ = 800 / 1.4

         v₁ = 571.4 m / min

section 2

distance interval 500 in a 1.6 min time interval

         v₂ = 500 / 1.6

         v₂ = 312.5 m / min

section 3

distance interval 1200 m in a time 2 min

         v₃ = 1200/2

         v₃ = 600 m / min

taking the speed of each section we can calculate the average speed

         

the distance traveled

        Δx = 800 + 500 + 1200

        Δx = 2500 m

the time spent

        Δt = 1.4 + 1.6+ 2

        Δt = 5 min

         v_average = Δx / Δt

         v_average = 2500/5

         v_average = 500 m / min

7 0
2 years ago
Other questions:
  • A tennis player who is recovering from an ankle injury and is not allowed to change directions can maintain her cardio fitness l
    12·2 answers
  • an 2-kg object is moving horizontally with a speed of 4m/s. how much net force os required to keep the object movong with the sa
    8·1 answer
  • A circular loop of wire is rotated at constant angular speed about an axis whose direction can be varied. In a region where a un
    7·1 answer
  • A large crate with mass m rests on a horizontal floor. The static and kinetic coefficients of friction between the crate and the
    5·2 answers
  • Our two intrepid relacar drivers are named Pam and Ned. We use these names to make it easy to remember: measurements made by Pam
    5·1 answer
  • A satellite is in circular orbit at an altitude of 1500 km above the surface of a nonrotating planet with an orbital speed of 9.
    11·1 answer
  • A skateboarder traveling at 4.45 m/s can be stopped by a strong force in 1.82 s and by a weak force in 5.34 s.
    5·1 answer
  • A fisherman is watching water waves ripple past his boat. How could he determine the wavelength of the water waves?
    9·1 answer
  • At a certain instant the current flowing through a 5.0-H inductor is 3.0 A. If the energy in the inductor at this instant is inc
    15·1 answer
  • Dave and Alex push on opposite ends of a car that has a mass of 875 kg. Dave pushes the car to the right with a force of 250 N,
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!