Answer:
The final rotation is 2.449 times the initial rotation
Explanation:
Centripetal acceleration and rotation speed of particle is related as
a=rω²
where ω is angular speed and r radius of circle
Rearranging equation
ω=
The initial acceleration is given by
a₁ =100g
The final acceleration of particle is
a₂ = 6 (100g)
=600g
The final and initial rotation speed are related as
ω2=
ω2=2.449ω1
Answer:
Explanation:
Force on a current carrying rod due to magnetic field is given as
here we know that
current in the rod
now magnetic force is balanced by the weight of the rod
so we will have
Good work on solving part a).
b) may look complicated, but it's not too bad.
It says that the body is 25% efficient in converting fat to mechanical energy.
In other words, only 25% of the energy we get from our stored fat shows up
in the physical, mechanical moving around that we do. (The rest becomes
heat, which dissipates into the environment as we keep our bodies warm,
breathe hot air out,and perspire.)
You already know how much mechanical energy the climber needed to lift
himself to the top of the mountain... 2.4x10⁶ joules.
That's 25% of what he needs to convert in order to accomplish the climb.
He needs to pull 4 times as much energy out of fat.
-- Fat energy required = 4 x (2.4 x 10⁶) = 9.6 x 10⁶ joules.
-- Amount stored in 1kg of fat = 3.8 x 10⁷ joules
-- Portion of a kilogram he needs to use = (9.6 x 10⁶) / (3.8 x 10⁷)
Note:
That much of a kilogram weighs about 8.9 ounces ... which shows why it's so
hard to lose weight with physical exercise alone. It also helps you appreciate
that fat is much more efficient at storing energy than batteries are ... that one
kilogram of fat stores the amount of energy used by a 100-watt light bulb, to
burn for 105 hours (more than 4-1/2 days ! ! !)
Answer:
230
Explanation:
= Rotational speed = 3600 rad/s
I = Moment of inertia = 6 kgm²
m = Mass of flywheel = 1500 kg
v = Velocity = 15 m/s
The kinetic energy of flywheel is given by
Energy used in one acceleration
Number of accelerations would be given by
So the number of complete accelerations is 230
