Answer:
a) 7200 ft/s²
b) 140 ft
c) 3.7 s
Explanation:
(a) Average acceleration is the change in velocity over change in time.
a_avg = Δv / Δt
We need to find what velocity the puck reached after it was hit by the hockey player.
We know it reached 40 ft/s after traveling 90 feet over rough ice at an acceleration of -20 ft/s². Therefore:
v² = v₀² + 2a(x − x₀)
(40 ft/s)² = v₀² + 2(-20 ft/s²)(100 ft − 10 ft)
v₀² = 5200 ft²/s²
v₀ = 20√13 ft/s
So the average acceleration impacted to the puck as it is struck is:
a_avg = (20√13 ft/s − 0 ft/s) / (0.01 s)
a_avg = 2000√13 ft/s²
a_avg ≈ 7200 ft/s²
(b) The distance the puck travels before stopping is:
v² = v₀² + 2a(x − x₀)
(0 ft/s)² = (5200 ft²/s²) + 2(-20 ft/s²)(x − 10 ft)
x = 140 ft
(c) The time the puck takes to travel 10 ft without friction is:
t = (10 ft) / (20√13 ft/s)
t = (√13)/26 s
The time the puck travels over the rough ice is:
v = at + v₀
(0 ft/s) = (-20 ft/s²) t + (20√13 ft/s)
t = √13 s
So the total time is:
t = (√13)/26 s + √13 s
t = (27√13)/26 s
t ≈ 3.7 s
To generate clean energy the mayor my build the fooling type of energy plants:
wind farms
solar power plants
wave power plants
Explanation:
At the seaside there are winds all over the year and that can be transformed in electrical energy by a wind turbine. The mayor can build a on-shore wind farm (reduced consts) and may also build off-shore wind farms (but these have an increased cost).
The second option is to build solar power plants. It will be cost effective if the people in the town will install solar panels on the building roofs. In this way you decrease the costs with the transportation of electrical energy.
The third option is to install wave power plants which harvest energy from the sea waves. It is a rather new technology, in comparison with the other two, but the initial consts can be amortized over time.
All three options will provide clean energy.
Right now nuclear plants have a very expensive initial costs and they may not be afforded by small towns.
Learn more about:
clean energy sources
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Answer:
a) total moment of inertia is 1359.05 kg m^2
b) angular acceleratio is 0.854rad/sec^2
Explanation:
Given data:
m1=6.9 kg
L=4.88 m
m2=34.5 kg
R=1.22 m
we klnow that moment of inertia for rod is given as
J1=(1/12) ×m×L^2
moment of inertia for sphere is given as
J1=(2/5) ×m×r^2
As object rotates around free end of rod then for sphere the axis around what it rotates is at a distance of d2=L+R
For rod distance is d1=0.5*L
By Steiner theorem
for the rod we get 
for the sphere we get 
And the total moment of inertia for the first case is
b) F=476 N
The torque for system is given as
where a is angle between Force and distance d
and where d represent distance from rotating axis.
In this case a = 90 degree
M=476*2.44 = 1161.44 Nm
The acceleration is calculated as
= 0.854 rad/sec^2
A stationary charge is located between the poles of a horseshoe magnet. The magnetic force exerted by the charge is zero.
<h3>What is charge?</h3>
Charge is the physical property of matter which cause a particle to attract or repel when placed in its field.
A stationary charged particle does not interact with a static magnetic field. A charge placed in a magnetic field experiences a magnetic force. There will be no magnetic force acting on a stationary charge. The charge must be moving in order to have magnetic force on it.
Thus, the magnetic force exerted by the charge is zero.
Learn more about charge.
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