The North Star, or Polaris, is the brightest star in the constellation Ursa Minor, the little bear (also known as the Little Dipper). As viewed by observers in the Northern Hemisphere, Polaris occupies a special place
Explanation:
The work done equals the change in energy.
W = ΔKE
W = 0 − ½mv²
W = -½ (0.270 kg) (-7.50 m/s)²
W = -7.59 J
Work is force times displacement.
W = Fd
-7.59 J = F (-0.150 m)
F = 50.6 N
Explanation:
Given parameters:
Distance = 180m
Time = 12s
Unknown:
Speed in m/s and km/hr
Solution:
Speed is the distance divided by the time taken,
Speed =
So;
Speed =
= 15m/s
1000m = 1km
3600s = 1hr
Therefore;
15 x m x
x
x
= 54km/hr