Answer:
V= 33.98 m/s
Explanation:
Given that
Horizontal speed ,u= 17 m/s
Time taken by rockets to strike the water ,t= 3 s
We know that acceleration due to gravity ,g= 9.81 m/s²
There is no any acceleration in the horizontal direction that is why the horizontal veloity will remain constant.
In the vertical direction
vy = uy+ g t
Initial velocity in vertical direction is 0 m/s.
vy= 0+ 9.81 x 3
vy = 29.43 m/s
The resultant velocity


V= 33.98 m/s
Force is directly proportional to mass according to the second law of Newton, meaning that the greater the mass is, bigger the force should be in order to move the object. In this case, Mutt's wagon has a mass two times greater than Jeff's and they have to be equal. So either Jeff must slow down twice as much or Mutt has to speed up twice as much. The only option we can choose according to our reasoning is that Mutt must use twice as much force to push his cart, because his mass is two times bigger. According to me the answer is C).
According to Doppler Effect, an observer at rest will perceive a shift in the wavelength or frequency of the radiation emitted by a source in movement.This shift is given by the formula:

where:

= observed wavelength

= wavelength at rest
v = speed of source (positive if towards the observer, negative if away from the observer)
c = speed of light
Therefore, we can solve for the observed wavelength:

Substituting the given data:

= 655.80 nm
Hence, the observed wavelength of the line would be
655.80 nm. Note that this value is smaller than the one at rest, which means that we have a blue-shift, as expected for an approaching source.
Answer:
200J
Explanation:
200J is 100%, 10% of 200J would be 20J