Yes an change in velocity either a decrease or increase is an acceleration.
Sound waves require a medium to travel through. :D
# 7 the answer is 4) because you need opposites in order to attract
# 8 I'm going to guess it is 4) because electricity is needed in order a light bolt to work.(don't take my word for this one I'm not sure but, the other answer are correct)
# 9 the answer is 4) because the comb dose collect negative charges from the hair in order to make the hair have positive charge.
Hope this helped : )
Answer:
nothing
Explanation:If you ride a bike around the block and return to the exact point where you started, your displacement is zero.
By definition, displacement involves changing an object from its original position. No matter how far or for how long a body moves, if it returns to the position it started from, it has not been displaced at all. This means that the body has zero displacements.
Answer:
There are many topics related to physics such as :
Kinematics
Dynamics
Light
Sound