D) Both A and B.
Francisco Redi must use 1)a covered, unrefrigerated meat and 2) an uncovered, refrigerated meat to experiment and test his hypothesis that maggots came from flies rather than from meat.
C. 340
Frequency is the number of wavelengths per second and since the length is 0.5 you multiply 0.5*686 and get 343.
the question not allowing for one position thus the answer is c
he basket ball diameter used by NBA men players is around 9.55 inches
So diameter = 9.55 inch = 0.243 m
So radius of basket ball = 0.1215 m
Volume , 

So volume of basket ball used by men NBA players = 7.5 L
Answer:
(a) -8064 N
(b) 8064 N
Explanation:
(a)
From Newton’s law of motion, Force, F=ma where m is mass and a is acceleration.
Since acceleration is the rate of change of velocity per unit time, then where v is velocity and the subscripts f and I denote final and initial
For the first ball, the mass is 0.28 Kg, final velocity is zero since it finally comes to rest, t is 0.00025 s and initial velocity is given as 7.2 s. Substituting these values we obtain

(b)
For the second ball, the mass is also 0.28 Kg but its initial velocity is taken as zero, the final velocity of the second ball will be equal to the initial velocity of the second ball, that is 7.2 m/s and the time is also same, 0.00025 s. By substitution

Here, we prove that action and reaction are equal and opposite
1) The braking force is provided by the frictional force, which is given by:

where
is the coefficient of friction
m=1500 kg is the mass of the car
is the gravitational acceleration
Substituting numbers into the equation, we find

2) The work done by the frictional force to stop the car is equal to the product between the force and the distance d:
(1)
where we put a negative sign because the force is in the opposite direction of the motion of the car.
3) For the work-energy theorem, the work done by the frictional force is equal to the variation of kinetic energy of the car:
(2)
The final kinetic energy is zero, so the variation of kinetic energy is just equal to the initial kinetic energy of the car:

4) By equalizing eq. (1) and (2), we find the distance, d:

