Answer:
12500W
Explanation:
Given parameters:
Work done = 250000J
Time taken = 20s
Unknown:
Power of the crane = ?
Solution:
Power is the defined as the rate at which work is being done;
Mathematically;
Power =
insert the parameters and solve;
Power = = 12500W
Answer:
F = -307.4 N
Explanation:
It is given that,
Mass of the baseball, m = 0.145 kg
Initial speed of the baseball, u = 60 m/s
Final speed of the baseball,
Time of contact,
(a) It is assumed to find the horizontal component of average force. It is given by :
F = -307.4 N
So, the horizontal component of average force is 307.4 N. Hence, this is the required solution.
Answer:
speed of star is 1.37 × m/s
it is approaching to earth because wavelength of star is decreasing than rest
if emit same wavelength it does not move anywhere
it will remain steady condition with respect earth
Explanation:
given data
wavelength = 656.5 nm
rest wavelength = 656.8 nm
to find out
the speed of the star , is it approaching
solution
we know here equation that is
wavelength shift / wavelength at rest = velocity of source / speed of light
so put all value and find
velocity of source = 3 × × 3 ×
/ 656.8 ×
velocity of source star = 1.37 × m/s
and
it is approaching to earth because wavelength of star is decreasing than rest
and
if emit same wavelength it does not move anywhere
it will remain steady condition with respect earth