Ok, so you've got to figure out a force F and you have the speed in which the boxer punches on determinate time and the mass of the sheet of paper.
So based on the formula that says that the Force is equal to the mass multiplied by the acceleration => F=ma.
You look at it and see that you only have mass which is measured on KG so there is no problem.
then you have the acceleration which is measured on meters and is defined by: a = Δv/Δt
So now you can replace the velocity and the time you have there
⇒ a 25m/s / 0.05s
you have computing that ⇒ 50m because the seconds were cancelled out.
and then you plug the meters into the force equation.
F=(0.005kg)(50)
F=0.25N
so the boxer will have a force of 0.25 Newton's.
Actually Welcome to the Concept of the Kinematics in real world.
So, as given here, we have to find the Mass of the bus from the given momentum, so we get as,
P = m * V
momentum = mass * velocity
here, P= 152625 kgm/s and v= 11.1 m/s
so substituting we get as,
m = 152625 ÷ 11.1 => 13,750 kg
hence,the mass of the bus is 13,750 kg.
Mass of oxygen stays the same.
(a) The electron kinetic energy is
which can be converted into Joule by keeping in mind that
So that we find
The kinetic energy of the electron is related to its momentum p by:
where m is the electron mass. Re-arranging the equation, we find
And now we can use De Broglie's relationship to find its wavelength:
where h is the Planck constant.
(b) By using the same procedure of part (a), we can convert the photon energy into Joules:
The energy of a photon is related to its frequency f by:
where h is the Planck constant. Re-arranging the equation, we find
And now we can use the relationship between frequency f, speed of light c and wavelength
of a photon, to find its wavelength: