Answer:
work done lifting the bucket (sand and rope) to the top of the building,
W=67.46 Nm
Explanation:
in this question we have given
mass of bucket=20kg
mass of rope=
height of building= 15 meter
We have to find the work done lifting the bucket (sand and rope) to the building =work done in lifting the rope + work done in lifting the sand
work done in lifting the rope is given as,
=
..............(1)
=
=22.5 Nm
work done in lifting the sand is given as,
.................(2)
Here,
F=mx+c
here,
c=20-18
c=2
m=
m=.133
Therefore,

Put value of F in equation 2


Therefore,
work done lifting the bucket (sand and rope) to the top of the building,
W=22.5 Nm+44.96 Nm
W=67.46 Nm
Answer: B - 8
Explanation: 8 protons because number of protons is equal to number of atoms in the nucleus.
When both particles, the electron and the proton move at the same speed, they may have differences with their de Broglie wavelength, the particle that would have a longer wavelength would be the proton since the wavelength is in direct proportionality with the mass of the particle.
Answer:
E = hv
Explanation:
- The photoelectric effect is a phenomenon when the electromagnetic waves of a particular wavelength strike on the metal plate like zinc, it ejects the free electrons.
- The ejected electrons have the kinetic energy and this energy is responsible for the electric energy.
- The kinetic energy of the emitted electrons is linked with the frequency of the incident rays.
- If the rays hitting the metal plate is below the minimum required threshold value, the photoelectrons are not ejected.
- The photoelectric equation is given by
E = hν - ∅
Where, ∅ is the minimum energy required to remove an electron.