Answer:
C. molecules speed up as more thermal energy is added
Explanation:
The molecules will simply speed up as more thermal energy is added to the solid.
Thermal energy is a form of kinetic energy which is set in motion.
- Heat causes kinetic energy build up in a body.
- As the molecules of the solid gains heat, they will continue to increase in thermal energy.
- They are forced to start vibrating about their fixed point.
- Thereafter, when they have enough energy, they break free from the forces holding them.
- Therefore, they move from a state of rest to one with a very high kinetic energy where the molecules moves rapidly.
- This is why a solid will change to liquid and sometimes eventually gas
Answer:
the total momentum is 8 .2 kg m/s in north direction.
Explanation:
given,
mass(m₁) 3.00 kg, moving north at v₁ = 3.00 m/s
mass(m₂) 4.00 kg, moving south at v₂ = 3.70 m/s
mass(m₃) 7.00 kg, moving north at v₃ = 2.00 m/s
north as the positive axis
south as the negative axis
now
total momentum = m₁v₁ + m₂ v₂ + m₃ v₃
total momentum = 3 x 3 - 4 x 3.7 + 7 x 2
= 9 - 14.8 + 14
= 8 .2 kg m/s
hence, the total momentum is 8 .2 kg m/s in north direction.
