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1 year ago

How much time does it take light to travel from the moon to the earth, a distance of 384000 km?

Physics

1 answer:

Natali5045456 [20]1 year ago

6 0

Answer:

1.28second

Explanation:

The speed of light is constant everywhere, it is

299,792,458m/s=299,792.458km/s

Therefore it takes

$\frac{384000}{299792458} = 1.28sec$

You might be interested in

How much heat is needed to melt 13.74 kg of silver that is initially at 20°C?

salantis [7]

Answer:

$Q = 4.63 \times 10^6 J$

Explanation:

As we know that melting point of silver is

T = 961.8 degree C

Latent heat of fusion of silver is given as

L = 111 kJ/kg

specific heat capacity of silver is given as

$s = 240 J/kg C$

now we will have

$Q = ms\Delta T + mL$

$\Delta T = 961.8 - 20$

$\Delta T = 941.8 degree C$

now from above equation

$Q = (13.74)(240)(941.8) + (13.74)(111 \times 10^3)$

$Q = 3.1 \times 10^6 + 1.53 \times 10^6$

$Q = 4.63 \times 10^6 J$

3 0

3 years ago

Find the momentum of a 25 kg remote

telo118 [61]

Answer:

100

Explanation:

Momentum (P) = Mass (M) × Velocity (V)

Momentum = 25kg × 4.0m/s

Momentum = 100kg m/s

7 0

3 years ago

A hiker determines the length of a lake by listening for the echo of her shout reflected by a cliff at the far end of the lake.

ArbitrLikvidat [17]

Answer:

L = 499 m

Explanation:

If we assume that the speed of sound is constant, that travels along a straight line, and that the echo is instantaneous, we can find the total distance travelled by the sound, as follows, just applying the definition of average velocity:

$\Delta x = v_{s} * t = 343 m/s* 2.91 s = 998 m$

If we assume that the time needed to reach to the cliff, is the same used for the return travel, the length of the lake will be exactly half of the total distance calculated:

$l_{lake} = \frac{\Delta x}{2} = \frac{998m}{2} = 499 m$