Answer:
27.44 J
Explanation:
We can find the energy at the top of the slide by using the potential energy equation:
At the top of the slide, the swimmer has 0 kinetic energy and maximum potential energy.
The swimmer's mass is given as 7.00 kg.
The acceleration due to gravity is 9.8 m/s².
The (vertical) height of the water slide is 0.40 m.
Substitute these values into the potential energy equation:
- PE = (7.00)(9.8)(0.40)
- PE = 27.44
Since there is 0 kinetic energy at the top of the slide, the total energy present is the swimmer's potential energy.
Therefore, the answer is 27.44 J of energy when the swimmer is at the top of the slide.
Answer:
Approximately 
, assuming friction between the vehicle and the ground is negligible.
Explanation:
Let 
denote the mass of the vehicle. Let 
denote the initial velocity of the vehicle. Let 
denote the spring constant (needs to be found.) Let 
denote the maximum displacement of the spring.
Convert velocity of the vehicle to standard units (meters per second):
.
Initial kinetic energy (
) of the vehicle:
.
When the vehicle is brought to a rest, the elastic potential energy (
) stored in the spring would be:
.
By the conservation of energy, if the friction between the vehicle and the ground is negligible, the initial 
of the vehicle should be equal to the 
of the vehicle. In other words:
.
Rearrange this equation to find an expression for , the spring constant:
.
Substitute in the given values 
, 
, and 
:
Answer: Matter is anything that has mass and takes up space . Mass is amount of mass that an object contains. Mass is measured by scale . Volume is amount of space that matter takes up .
Explanation:
Answer:
The velocity of the composite body is 0.99m/s 63.43° west of north.
Explanation:
Here the law of conservation of energy says that
where 
is the final velocity if the composite body, and 
is measured from west of north.
Putting in numbers and simplifying the above equation we get:
dividing equation (4) by (3) gives
putting in 
, 
, 
, and 
we get:
Thus, the final velocity we get from equation (3) is:
Thus, the velocity of the composite body is 0.99m/s 63.43° west of north.
Answer:
Electron.
From plastic rod to metal sphere.
Explanation:
The charged plastic rod is negatively charged, which means it contains excess electrons.
After they touch each other, the plastic rod now has a more positive value.
Since the sphere is a metal sphere, it is able to conduct the flow of electrons.
Hence, the plastic rod has given off some of its electrons to the metal sphere.
