Clouds and fog and it may rain or snow
Answer:
(5) It depends on whether the collision was elastic or inelastic.
Explanation:
Due to the absence of external forces and the fact that masses and initial velocities are known, it is needed to determine if collision is elastic or inelastic. If collision is inelastic, the Momentum Principle is sufficient to calculate final momentum, but if it is elastic, the Momentum Principle should be complemented with the application of the Energy Principle.
Hence, the correct answer is (5).
Answer:
44J
Explanation:
Given parameters:
Mass of rock = 0.22kg
Initial velocity = 20m/s
Distance moved = 10m
Unknown:
Initial kinetic energy of the rock = ?
Solution:
To solve this problem, we need to understand that kinetic energy is the energy due to the motion of a body.
It is mathematically expressed as;
Kinetic energy = 
m v²
m is the mass
v is the velocity
Kinetic energy = x 0.22 x 20² = 44J
Answer:
A) is repelled by the sphere.
Explanation:
On rubbing the plastic rod with the wool cloth the rod gains some electrons from the surface of the wool and becomes electrostatically negative in charge.
When this rod is brought near to a neutral metallic sphere then the electrons of the sphere get repelled from the nearest portion of the metallic sphere as it a conductor and the electrons accumulate on the farthest opposite side of the rod.
But when the rod is brought into contact for some time then the from the portion of the rod which is in contact to the sphere loses the electrons from that region to the sphere since plastic is not an electrical conductor so not all the charges travel to the sphere.
Then when the rod is separated, the charges on the sphere spread uniformly and the similar charged rod faces repulsion.
