It could be one of this 0.2m/s/s
or 0.5m/s/s.
Explanation:
Contact force is any force that requires contact. An object that exerts a force on another object by touching it is exerting a contact force. Examples of contact force are friction and normal force.
Examples of a non-contact force are gravity and magnetism.
Answer:
150J
Explanation:
work output/work input=100%
so just make work output the subject
Answer:
See Explanation
Explanation:
m1(v1) + m2(v2)
Opposite turns the plus to subtraction.
80(8) - 120(4.0)
60 - 480 = 160 kg m/s to the right
Answer : The energy of one photon of hydrogen atom is, 
Explanation :
First we have to calculate the wavelength of hydrogen atom.
Using Rydberg's Equation:

Where,
= Wavelength of radiation
= Rydberg's Constant = 10973731.6 m⁻¹
= Higher energy level = 3
= Lower energy level = 2
Putting the values, in above equation, we get:


Now we have to calculate the energy.

where,
h = Planck's constant = 
c = speed of light = 
= wavelength = 
Putting the values, in this formula, we get:


Therefore, the energy of one photon of hydrogen atom is, 