Answer:
0.83m/s
Explanation:
Given parameters:
distance = 1000m
time taken = 20min
Unknown:
Speed of the walking person = ?
Solution:
To solve this problem;
Speed =
Time taken should be in seconds;
1 min = 60s
20min = 20 x 60 = 1200s
Speed = = 0.83m/s
Answer:
c) At a distance greater than r
Explanation:
If G= Gravitational constant
M= Mass of earth
r= distance from earth center
then orbital speed is ;
v =
==> v²=GM/r
If speed of first satellite = V₁
==> V₁² = GM/r
==> r = GM/V₁²
If speed of second satellite say V₂ is less than V₁ then square of V₂ will be less than square of V₁ , and hence GM will be divided by less number in case of second satellite, and hence will give greater value of r as compared to first satellite.
So our answer is c