a machine for converting the energy of falling water into useful forms of power and it is also known as a watermill
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 answer to your question is Pe = 2452.5 J
Explanation:
Data
mass = 50 kg
height = 5 m
gravity = 9.81 m/s²
Process
The energy of this process is Potential energy which is proportional to the mass of the body, the gravity and the height of the body.
Pe = mgh
Substitution
Pe = (50)(5)(9.81)
Simplification
Pe = 2452.5 J
Answer:
The surface gravity is inversely proportional to the square of the radius of the planet
Explanation:
The gravity at the surface of a planet is given by:
where
G is the gravitational constant
M is the mass of the planet
R is the radius of the planet
We see from the formula that the surface gravity is inversely proportional to the square of the radius of the planet, R.
At the Earth's surface, the value of the surface gravity is approximately 9.81 m/s^2.
Initial speed = 56mph
Final speed = 35mph
Time taken = 6.7seconds...
Converting the time to hour.. Divide by 3600..
= 6.7/3600
=0.00186hour..
Acceleration = v-u/t
a = 35-56/0.00186
a = -11283.6mph²
The negative sign shows that it decelerated...
V² = u²+2as
(35)² = (56)² + 2×-11283.6×s
Where s is the distance covered within that time...
1225 = 3136 - 22567.2s
22567.2s = 3136-1225
22567.2s = 1911
S = 1911/22567.2
S = 0.08468miles...
But at the end of the question we were made to understand that 1miles = 5280ft
Therefore 0.08468miles = (0.08468×5280)ft
= 447. 11feets...
Which is approximately 447ft.....
Hope this helped.... ?
