Answer:
The initial speed of bullet is "164 m/s".
Explanation:
The given values are:
mass of bullet,
or,
mass of wooden block,
speed,
Coefficient of kinetic friction,
As we know,
The Kinematic equation is:
⇒ 
then,
Initial velocity will be:
⇒ 
On substituting the given values, we get
⇒ 
As we know,
The conservation of momentum is:
⇒ 
or,
⇒ Initial speed, 
On substituting the values, we get
⇒ 
⇒ 
⇒ 
A mechanical wave must have a medium.
Hope this helps,
♥<em>A.W.E.<u>S.W.A.N.</u></em>♥
Answer:
(A) The speed just as it left the ground is 30.25 m/s
(B) The maximum height of the rock is 46.69 m
Explanation:
Given;
weight of rock, w = mg = 20 N
speed of the rock at 14.8 m, u = 25 m/s
(a) Apply work energy theorem to find its speed just as it left the ground
work = Δ kinetic energy
F x d = ¹/₂mv² - ¹/₂mu²
mg x d = ¹/₂m(v² - u²)
g x d = ¹/₂(v² - u²)
gd = ¹/₂(v² - u²)
2gd = v² - u²
v² = 2gd + u²
v² = 2(9.8)(14.8) + (25)²
v² = 915.05
v = √915.05
v = 30.25 m/s
B) Use the work-energy theorem to find its maximum height
the initial velocity of the rock = 30.25 m/s
at maximum height, the final velocity = 0
- mg x H = ¹/₂mv² - ¹/₂mu²
- mg x H = ¹/₂m(0) - ¹/₂mu²
- mg x H = - ¹/₂mu²
2g x H = u²
H = u² / 2g
H = (30.25)² / 2(9.8)
H = 46.69 m
Answer: The elimination of seasonal variations
Explanation:
Since the cosmic catastrophic event which occurred led to the tilt of the Earth's axis relative to the plane of orbit to increase from 23.5° to 90°, the most obvious effect of this change would be the elimination of seasonal variations.
It should be noted that seasonal variation refers to the variation in a time series that's within a year which is repeated. The cause of seasonal variation can include rainfall, temperature, etc.
