Answer the following questions
Answers
Given:
Depth of the fall = 48m
Value of g= 9.8 m/s²
Initial Velocity = 0m/s
To Find:
A) How long did Munday fall to reach the water surface below the falls?
B) What was Munday's velocity as he reached the water surface?
C) What was Munday's velocity after a period of 1s?
D) When do we say that an object undergoes retardation?
Solution:
A) Since acceleration is constant, we can use 2nd equation of motion.
s = ut + 1/2 a t²
Since u = 0 m/s
and s = 48m
-48 = 1/2 (-9.8) t²
or t = 3.12 s
B) Using 1st equation of motion,
v = u + at
Substituting the value of t from (A)
v = 0 + (-9.8) (3.12)
v = - 30.57m/s
C) To find velocity after 1 s, we can use the 1st equation of motion.
v1 = u + at
taking t = 1 s
v1 = 0 + (-9.8) (1)
v1 = -9.8m/s
D) An object undergoes retardation when its net negative acceleration is in opposite direction to that of the object's velocity.
Answer:
Time =3.12s
v =30.57m/s
velocity after 1 s =9.8m/s
Explanation:
Initial velocity is =0m/s
Acceleration g= 9.8m/s
Depth of fall =48m
Time taken Munday fall to reach the water surface below the fall.
u =0m/s
s =48m
48 =1/2(9.8)2
t=3.12s
Munday 's velocity as he reach the water surface
v=0+9.8*3.12
v= 30.57m/s
Munday's velocity after a period of 1s
v'=u+ at
v' =o+(9.8)1
v'= 9.8m/s
We say the object goes retardation when negative force of speed oppose the velocity.
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