A. One substance must dissolve in another
Answer: option A) initially increases, then decreases.
Justification:
The increase of the rate of effective collisions among particles as the temperature increases is explained by the collision theory in virtue of the increase of the kinetic energy.
This is, as the temperature increase so the kinetic energy increase and the higher the kinetic energy the greater the number of collisions and the greater the chances that this energy overcome the activation energy (the energy needed to start the reaction).
Now, as the reaction progress the number of reactants particles naturally decrease (some of them have been converted into product) so this lower number of particles means lower concentration which means lower collisions and, thereafter, a decrease in the reaction rate.
At the top:
Potential Energy = (mass) x (gravity) x (height)
= (30 kg) x (9.8 m/s²) x (3 meters)
= 882 joules
At the bottom:
Kinetic Energy = (1/2) x (mass) x (speed)²
= (1/2) x (30 kg) x (3 m/s)²
= (15 kg) x (9 m²/s²)
= 135 joules .
He had 882 joules of potential energy at the top,
but only 135 joules of kinetic energy at the bottom.
Friction stole (882 - 135) = 747 joules of his energy while he slid down.
The seat of his jeans must be pretty warm.
Answer:
The light rays falling on a rough surface does follow the laws of reflection. The light rays are incident parallel on the rough surface but due to uneven surface the light rays are not reflected parallel rather they are reflected in different direction. Hence, no image is formed.
