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:
C. It is radiation leftover from the Big Bang
F=mg=Gm1m2/r^2
g=Gm2/r^2
g=2Gm2/(2r)^2=2Gm2/4r^2=Gm2/2r^2
So since there is half times the gravity on this unknown planet that has twice earth's mass and twice it's radius, then the person can jump twice as high. 1.5*2= 3m high
ΔU =
-Wint
Consdier the work of of
interaction is W =m*g*h - equation -1
and the Potential energy U.
Final Potential energy Uf =0
, And the Initial Potential Energy Ui =m*g*h
<span>Now we will write the
equation for a Change in Potential energy ΔU,</span>
ΔU = Uf
- Ui
= 0-m*g*h
<span> ΔU = -m*g*h --Equation 2</span>
Now compare the both equation
<span>Wint = -ΔU</span>
we can rewrite the above
equation
ΔU =
-W.
<span>So our Answer is ΔU = -W. .</span>
<span> </span>
The largest transition metal is copernicium with 112 protons.
