Answer:
A. Red, Green, Blue
B. None. They all hit the ground with the same speed.
C. Final Kinetic Energy = Initial Gravitational Potential Energy
Explanation:
A. This one is actually just common sense. If you think about it, the object that is being thrown downward will reach the ground first. The object thrown upwards will hit the ground the last. If you don't believe me, use just the vertical component of velocity and use acceleration = 9.8 m/s^2. Find the time it takes for an arbitrary displacement each ball will travel. You will find that the one pointed downward will reach the ground in the shortest amount of time. Just do the same math over for the rest of the balls and you can find the time it takes for each ball to hit the ground.
B. This one is actually really simple if you think about it. Using the Work-Energy theorem, using the system consisting a ball and the earth there will be no external forces doing work on the system. Since each ball is at some height "h" and the same initial speed, they will all have the same amount of energy in the beginning. If we set the ground as our reference point for gravitational potential energy, then there will be no gravitational energy as the height at that point will be 0. They all must have the same kinetic energy at the ground.
C.
Mechanical Energy Final = Mechanical Energy Initial + Net Work from non-conservative forces
Kinetic Energy Final + Gravitational Potential Energy Final = Kinetic Energy Initial + Gravitational Potential Energy Initial
I am using the symbol " ' " to indicate final speeds and heights
0.5*m*v'^2 + mgh' = 0.5*m*v^2 + mgh
0.5*m*v'^2 + 0 = 0.5*m*v^2 + mgh
(cancel out the mass)
0.5*v'^2 = 0.5*v^2 +gh
Since the "v" is the same initially for all three balls and "g" and "h" are the same for all three balls. The final speed v' must be the same for all three situations regardless of mass.
If you have any questions feel free to comment again. I'll try to clarify.
Answer:
(a) There are 3.17 times more shakes in a second than seconds in a year.
(b) Humans have existed for 9067.72 universe seconds.
Explanation:
(a) First we calcule how many seconds are in a year. One year have 365 days, one day has 24 hours, one hour has 60 minutes and one minute has 60 seconds, so:
Now, we calculate how many shakes are in a second:
Finally, we calculate how many more shakes in a second are there than seconds in a year:
(b) Using a simple rule of three we can calculate how many "universe seconds" have humans existed, recall that 1 day has 86400 seconds:
1010 years--------->86400s
106 years----------> x seconds
Answer:
Explanation:
The Term "For every action, there is an equal and opposite reaction" is derived from Newton's third law of motion.
This can be explained by an example of a block placed on the flat surface.
The weight of the block applies an action force on the surface while Surface applies a reaction force on the block. Action and reaction force applies to different bodies other would have canceled each other. Action and reaction forces are always acting in pairs. The magnitude of reaction force depends upon the action forces as both of them are equal in magnitude but opposite in direction.
Answer:
Hz
Explanation:
We know that
1 cm = 0.01 m
= Length of the human ear canal = 2.5 cm = 0.025 m
= Speed of sound = 340 ms⁻¹
= First resonant frequency
The human ear canal behaves as a closed pipe and for a closed pipe, nth resonant frequency is given as
for first resonant frequency, we have n = 1
Inserting the values
Hz
Answer:
n=6.56×10¹⁵Hz
Explanation:
Given Data
Mass=9.1×10⁻³¹ kg
Radius distance=5.3×10⁻¹¹m
Electric Force=8.2×10⁻⁸N
To find
Revolutions per second
Solution
Let F be the force of attraction
let n be the number of revolutions per sec made by the electron around the nucleus then the centripetal force is given by
F=mω²r......................where ω=2π n
F=m4π²n²r...............eq(i)
as the values given where
Mass=9.1×10⁻³¹ kg
Radius distance=5.3×10⁻¹¹m
Electric Force=8.2×10⁻⁸N
we have to find n from eq(i)
n²=F/(m4π²r)
