An athlete with a mass of 65.5 kg is in a cross country race, and at one instant he has a speed of 4.20 m/s. (a) What is his kin
1 answer:
Answer:
(A) Kinetic energy will be 577.7 j
(b) Factor by which kinetic energy will change is 4
Explanation:
We have given mass of the athlete m = 65.5 kg
He has a speed of 4.20 m/sec
So v = 4.20 m/sec
(a) Kinetic energy is given by
(B) Now he wishes to doubles his speed So now speed = 4.20×2 = 8.40 m/sec
Now kinetic energy is
So the factor by which kinetic energy will change
You might be interested in
The right hand rule to find the direction of the magnetic field for a falling bar is:
- The charge is positive the magnetic field is outgoing, horizontally and towards us.
- The charge of the bar is negative, the magnetic field is incoming, that is horizontal away from us.
The magnetic force is given by the vector product of the velocity and the magnetic field.
F = q v x B
Where the bolds indicate vectors, F is the force, q the charge on the particle, v the velocity and B the magnetic field.
In the vector product, the vectors are perpendicular, which is why the right-hand rule has been established, see attached:
- The thumb points in the direction of speed.
- Fingers extended in the direction of the magnetic field.
- The palm is in the direction of the force if the charge is positive and in the opposite direction if the charge is negative.
They indicate that the bar is dropped, therefore its speed is vertical and downwards, it moves to the left therefore this is the direction of the force, we use the right hand rule, the magnetic field must be horizontal, we have two possibilities:
- If the charge is positive the magnetic field is outgoing, horizontally and towards us.
- If the charge of the bar is negative, the magnetic field is incoming, that is, horizontal away from us
In conclusion using the right hand rule we can find the direction of the magnetic field for a falling bar is:
- The charge of the bar is negative, the magnetic field is incoming, that is horizontal away from us.
- The charge is positive the magnetic field is outgoing, horizontally and towards us.
Learn more about the right hand rule here: brainly.com/question/12847190
Answer:
4.6 m
Explanation:
First of all, we can find the frequency of the wave in the string with the formula:
where we have
L = 2.00 m is the length of the string
T = 160.00 N is the tension
is the mass linear density
Solving the equation,
The frequency of the wave in the string is transmitted into the tube, which oscillates resonating at same frequency.
The n=1 mode (fundamental frequency) of an open-open tube is given by
where
v = 343 m/s is the speed of sound
Using f = 37.3 Hz and re-arranging the equation, we find L, the length of the tube: