The speed of the tennis ball is 8 km/h when Alana throws the ball behind at the speed of 11 km/h.
<h3>What is the
frame of
reference?</h3>
It is a point from where the motion is observed. The speed changes with the frame of reference.
For the person standstill on the sidewalk, If Alana throw the ball in the front direction, The speed will be,
19+11 = 30 km/h
It Alana just leave the ball, the speed,
19 +0 = 19 km/h
If Alana throws the ball behind her at the speed of 19 km/h. The speed of the ball for a sidewalk observer,
19 +(-19 ) = 0 km/h
Thus, when Aana throw the ball behind the velocity will be negative,
So,
19 + (-11 ) = 8 km/h
Therefore, the speed of the tennis ball is 8 km/h when Alana throws the ball behind at the speed of 11 km/h.
Learn more about Frame of reference:
brainly.com/question/9820962
Answer:
W = 16.5 Kj
P = 49.9 Watt
E = 16471
Explanation:
m = 73.5kg
t = 5min 30sec = (5×60) + 30 = 330sec
each step = 16.6cm = 0.166m
h = 135×0.166 = 22.41 m
g = 10 m/s²
(i) W = F × s = W × h = mgh
W = 73.5×10×22.41 = 16471.35
W = 16.5 Kj
(ii) Power = workdone/time
P = 16471.35/330
P = 49.9 Watt
(iii) The energy burnt in this process = 16471
Answer:
a)0.5564c
b)43.6 m
Explanation:
Given proper length of falcrum L₀= 43.6 m
improper length L=30.1 m (when viewed from moving frame)
we know that 

⇒
=



v=0.5564c
this is the required speed of falcon when it passes luke
b). Since Han solo is on the Falcon its reference frame will be falcon itself hence there wont be any change in the length of Falcon that its length will be
43.6 m
Inertia is when a object in motion will stay in motion or in a standing still state unless acted upon by a unbalancing force.
Friction is when a object slows down because it is rubbing against another object.
If a object is sliding across a surface, theoretically, it would not stop but because it is on a flat surface it would experience friction, this will disperse some of the kinetic energy that it has thus slowing the object down eventually, after some time, to a stop.
Hope this helps! :)
Answer:
For a solar eclipse to occur the moon must be between the earth and the sun (the light of the sun is blocked)'
By definition this is a new moon (which occurs when the moon cannot be seen because it is located between the sun and the earth).