Speed of Light Video Quiz | Clocks & Time Dilation

First, tell us who you are

First and last name School email

1What is a photon clock?

A clock that uses bouncing photons between two mirrors to measure timeA clock powered by photon energyA traditional mechanical clock used in spaceshipsA clock that measures photon speed

2According to Einstein, how does a photon clock look when observed from outside a moving spaceship compared to inside?

The photon travels a diagonal longer path making the clock appear slowerThe photon travels vertically and the clock speed is unchangedThe photon stops moving and the clock stops tickingThe photon moves faster so the clock appears faster

3What happens to the ticking rate of real physical clocks when they move at very high speeds?

They tick slowerThey tick fasterThey stop tickingThey tick at the same rate

4True or False: The speed of light is the same in all reference frames.

TrueFalse

5What happens to the half-life of muons traveling close to the speed of light?

It becomes about 10 times longerIt becomes shorterIt stays the sameMuons decay instantly

6Why can't objects be accelerated to the speed of light?

It takes infinite energy because time dilation slows the acceleration processBecause forces stop working at high speedsObjects melt before reaching speed of lightLight slows down objects

7What is the 'proper time' in relativity?

Time measured in the rest frame of the clock or observerTime measured by an outside observerTime that stops when objects move fastAn incorrect concept in physics

8What is the 'dilated time'?

Time measured by an observer seeing the moving clock, which appears longerTime measured by the moving observerTime time multiplied by speedAn unrelated concept

9How is the factor 'gamma' related to speed in time dilation?

Gamma is greater than 1 and increases as speed approaches the speed of lightGamma is less than 1 at high speedsGamma is constant regardless of speedGamma decreases as speed approaches light speed

10At 87% of the speed of light, what is the approximate value of gamma and the corresponding time dilation effect?

Gamma is about 2, so dilated time is twice the proper timeGamma is 1, no time dilationGamma is 0.5, time appears to speed upGamma is 22, huge time dilation

11If a spaceship accelerates at a constant force outward and approaches light speed, how does outside observers perceive its acceleration?

The acceleration appears to slow down due to time dilationAcceleration increases indefinitelyAcceleration remains constantAcceleration reverses direction

12Why does increasing the fuel output at high speeds not allow a spaceship to reach the speed of light faster?

Because to keep acceleration constant, fuel must increase indefinitely due to time dilationFuel is wasted at high speedsFuel is converted to light speed energyBecause engines stop working

13True or False: Experiments with atomic clocks on airplanes confirm time dilation predictions.

TrueFalse

14What fundamental postulate does all of special relativity, including time dilation, depend on?

The speed of light is constant in all reference framesMass increases to infinityTime flows differently everywhereEnergy is always conserved

15What causes the time dilation effect physically, according to the photon clock analogy?

Photons take a longer diagonal path because of the motion, making processes appear slowerPhotons slow down in moving framesPhotons speed up to transfer energy fasterThe distance between mirrors shrinks