Answer:
The answer is "telescopes".
Explanation:
Throughout ancient times, astronomical observatories have indeed been available, and so many historical locations were reserved for astronomical observations. All contemporary astronomers lacked within those older telescopes were lenses until 1610. A telescope is indeed an instrument used to view far-off objects. Telescopes often are being used to look at planets and stars.
Speed of wave is given as
Wavelength of the wave is given as
now from the formula of wave time period we can say
so it will have time period of T = 4 s
Answer:
40 N
Explanation:
F=ma where F is the applied force, m is the mass of object and a is the acceleration.
Since there is no friction, substituting 20 Kg for m and 2 m/s squared for a then we obtain
F=20*2=40 N
We don't know the change in velocity, so can't answer.
If the moon was hit by an asteroid there would be a crater mark and possible movement.