B) A ladybug crawling forward at constant rate of 2.5 m/s
Answer:
option B.
Explanation:
The correct answer is option B.
when the ball drops, the velocity of the ball before the collision is v
After the collision, the velocity of the ball is the same but in the opposite direction.
Impulse delivered to the ball and the floor, in this case, is not zero.
The magnitude of the momentum remains the same but the direction of the ball changes.
Explanation:
kinetic energy is energy that it possesses due to its motion.
Answer:
2.2nC
Explanation:
Call the amount by which the spring’s unstretched length L,
the amount it stretches while hanging x1
and the amount it stretches while on the table x2.
Combining Hooke’s law with Newton’s second law, given that the stretched spring is not accelerating,
we have mg−kx1 =0, or k = mg /x1 , where k is the spring constant. On the other hand,
applying Coulomb’s law to the second part tells us ke q2/ (L+x2)2 − kx2 = 0 or q2 = kx2(L+x2)2/ke,
where ke is the Coulomb constant. Combining these,
we get q = √(mgx2(L+x2)²/x1ke =2.2nC
