Answer:
The velocity of the ball before it hits the ground is 381.2 m/s
Explanation:
Given;
time taken to reach the ground, t = 38.9 s
The height of fall is given by;
h = ¹/₂gt²
h = ¹/₂(9.8)(38.9)²
h = 7414.73 m
The velocity of the ball before it hits the ground is given as;
v² = u² + 2gh
where;
u is the initial velocity of the on the root = 0
v is the final velocity of the ball before it hits the ground
v² = 2gh
v = √2gh
v = √(2 x 9.8 x 7414.73 )
v = 381.2 m/s
Therefore, the velocity of the ball before it hits the ground is 381.2 m/s
Answer:
70.07 Hz
Explanation:
Since the sound is moving away from the observer then
and 
when moving towards observer
With 
of 76 then taking speed in air as 343 m/s we have
Similarly, with of 65 we have
Now
v_s=27.76 m/s
Substituting the above into any of the first two equations then we obtain
Answer:
If child weight is equal to rope force then child will move with uniform speed
or we can say that the child will remain at rest in his position
Explanation:
As we know that child is hanging by rope
so here there will be two forces on the child
1) Weight or gravitational force which act vertically downwards
2) Tension in the rope which act vertically upwards
Now if child will accelerate upwards then tension force must be more than the weight of the child
If tension force is less than the weight then child will decelerate and his speed will decrease
if tension force is equal to child weight then in that case the child will remain at rest or it will move with same speed
Answer:
v ≈ 7900 m/s
Explanation:
centripetal force will equal gravity force
mv²/R = mg
v²/R = g
v² = Rg
v = √(Rg)
v = √(6.4e6(9.8))
v = 7.91959...e+3
v ≈ 7900 m/s
of course, at those velocities and that deep into the atmosphere, the satellite would quickly burn up, slow down, and cause tremendous damage to buildings etc. with the sonic boom shock wave. It would also have to avoid a lot of mountains as 4000 m is not that high.
You're fishing for "polarization".
