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:
Explanation:
Resistivity is given by
where A is cross-sectional area, R is resistance, L is the length and
is the reistivity. Substituting 0.0625 for R, 3.14 × 10-6 for A and 3.5 m for L then the resistivity is equivalent to
Answer
given,
mass of glider = 0.23 Kg
spring constant = k = 4.50 N/m
spring stretched to 0.130 m
The springs potential energy =


U = 0.038 J
at x = 0,the only energy will be kinetic .


v² = 0.3304
v = 0.575 m/s
displacement of the glider
using conservation of energy



x = 0.678 m
For fundamental frequency of a string to occur, the length of the string has to be half the wavelength. That is,
1/2y = L, where L = length of the string, y = wavelength.
Therefore,
y = 2L = 2*0.75 =1.5 m
Additionally,
y = v/f Where v = wave speed, and f = ferquncy
Then,
v = y*f = 1.5*220 = 330 m/s
Answer:
C) The function F(x) for 0 < x < 5, the block's initial velocity, and the value of Fr.
Explanation:
Yo want to prove the following equation:

That is, the net force exerted on an object is equal to the change in the kinetic energy of the object.
The previous equation is also equal to:
(1)
m: mass of the block
vf: final velocity
v_o: initial velocity
Ff: friction force
F(x): Force
x: distance
You know the values of vf, m and x.
In order to prove the equation (1) it is necessary that you have C The function F(x) for 0 < x < 5, the block's initial velocity, and the value of F. Thus you can calculate experimentally both sides of the equation.