B) 1950-1959
Sputnik I was launched on October 4, 1957
Answer:
20 m/s/s
Explanation:
F=ma, 350=17.5 * a, a=20 m/s/s
Answer:
6.93 km/h
Explanation:
To calculate her average speed, we need the "speed" formula, which is:
average speed = distance / time
You plug in your numbers and it will give you the answer.
Speed = 4.5km/0.65hr
= 6.923 km/h
Answer:
C. 5.6 × 10^11 N/C
Explanation:
The electric field 
at a distance 
from a charge 
is given by
where 
is the coulomb's constant.
Now, in our case
;
therefore,
which is choice C from the options given<em> (at least it resembles it).</em>
Answer:We have , a relation in frequency f and wavelength λ of a wave having the velocity v as ,
v=fλ ,
given f=60Hz , λ=20m ,
therefore velocity of wave , v=60×20=1200m/s
