When an object is acted on by an unbalanced force, then that object will accelerate.
Answer:
The value is 
Explanation:
From the question we are told that
The time taken to travel to the planet from earth is 
The time to be spent on the ship is
Generally speed can be obtained using the mathematical relation represented below

The 2 in the equation show that the trip is a round trip i.e going and coming back
=> 
=> 
Answer:
Light does not need a medium to travel travel through, but since waves must have a medium to vibrate, sound is not created where no air is present.
Explanation:
Answer:
jejjdedjd sidjjejdd jsms
Explanation:
jdjdndjdjjdj jsnssjns jsjsjs
Answer:
= 2.33
Explanation:
.According to snell's law:
n1sin i = n2sin r ,
where n1 is refractive index of the medium in which incident ray is travelling, n2 is the refractive index of the medium in which refracted ray is travelling,
i is angle of incidence,
r is angle of refraction.
Given that,
n1 = 1,
i = 51 degrees,
r = 19.5 degrees. ,
n2= ?
So,
1*sin 51 = n2 sin 19.5
=> n2 = sin51 / sin19.5
= 2.33