Sound waves are longitudal waves meaning they go back and forth
Explanation:
Given that,
The initial velocity of a skater is, u = 5 m/s
She slows to a velocity of 2 m/s over a distance of 20 m.
We can find the acceleration of skater. It is equal to the rate of change of velocity. So, it can be calculated using third equation of motion as follows :

a = acceleration

So, her acceleration is
and she is deaccelerating. Also, her initial velocity is given i.e. 5 m/s.
The answer is A
Explanation: the conservation of matter means that the mass stays the same
Answer: 3.75 joules
Explanation:
Given that:
Mass of acorn = 0.300 kilograms
velocity = 5.oo m/s
Kinetic energy = ?
Since, kinetic energy is the energy possessed by a moving object, its value depends on the mass M and velocity V of the acorn.
Thus, Kinetic energy = 1/2 x mv^2
= 1/2 x 0.300kg x (5.00m/s)^2
= 0.5 x 0.3kg x (5.00m/s)^2
= 0.15 x (5.00m/s)^2
= 3.75 joules
Thus, the kinetic energy of the falling acorn is 3.75 joules