Answer:
The mass has likely lost some of its mechanical energy to resistance on its path.
Explanation:
The mechanical energy of an object is the sum of its kinetic and potential energies (KE and PE.) Ideally, the mechanical energy of a simply pendulum should be "conserved." In other words, the sum of the kinetic and potential energy of the simply pendulum should stays the same as it travels along its path.
Indeed, as the pendulum travels, some of its PE will convert to KE and back. However, the sum of these two energies is supposed to stay the same.
- When the pendulum moves from the highest point to the bottom of the path, some of its PE converts to KE. (The pendulum speeds up in this process.)
- When the pendulum moves from the bottom of its path to the opposite side, its KE is converted back to PE. (The pendulum slows down as it moves towards the other side of the path.)
However, in practice, the mechanical energy of pendulums isn't always conserved. For example, various kinds of resistances (such as air resistance) act on the pendulum as it moves. That would slow down the pendulum. Some of the pendulum's energies would be converted to heat and is lost to the surroundings.
In effect, the mechanical energy of the pendulum would become smaller and smaller over time. When the pendulum travels back towards the girl, its potential energy would be smaller than the initial value when at the girl's chin.
The initial speed of the bolt is not 58.86 m/s.
Let a be the acceleration of the rocket.
During the 4 sec lift off, the rocket has reached a height of
h = (1/2)*a*t^2
with t=4,
h = (1/2)*a^16
h = 8*a
Its velocity at 4 sec is
v = t*a
v = 4*a
The initial velocity of the bolt is thus 4*a.
During the 6 sec fall, the bolt has the initial velocity V0=-4*a and it drops a total height of h=8*a. From the equation of motion,
h = (1/2)*g*t^2 + V0*t
Substituting h0=8*a, t=6 and V0=-4*a into it,
8*a = (1/2)*g*36 - 4*a*6
Solving for a
a = 5.52 m/s^2
Answer:
Geothermal energy can heat, cool, and generate electricity: Geothermal energy can be used in different ways depending on the resource and technology chosen—heating and cooling buildings through geothermal heat pumps, generating electricity through geothermal power plants, and heating structures through direct-use
Explanation:
Answer a) is incorrect as sound does not travel in a vacuum.
Answer:
C
Sign-Negative
Explanation:
We are given that
Electric field =
(Radially downward)
Acceleration=
(Upward)
Mass of charge=3 g=
kg
1kg=1000g
We have to find the magnitude and sign of charge would have to be placed on a penny .
By newton's second law
Substitute the values then we get
Substitute the values then we get
C
Sign of charge =Negative
Because electric force acting in opposite direction of electric field therefore,charge on penny will be negative.
