A cell is made up of molecules and molecule is made up of atoms. So, they both need molecules to be made.
Answer:
If the observer is stationary but the source moves toward the observer at a speed vs, the observer still intercepts more waves per second and the frequency goes up. This time it is the wavelength of the wave received by the observer that is effectively shifted by the motion, rather than the speed.
Answer:
b. The side the boy is sitting on will tilt downward
Explanation:
Initially, the seesaw is balanced because the torque exerted by the boy is equal to the torque exerted by the girl:

where
Wb is the weight of the boy
db is the distance of the boy from the pivot
Wg is the weight of the girl
dg is the distance of the girl from the pivot
When the boy moves backward, the distance of the boy from the pivot (
increases, therefore the torques are no longer balanced: the torque exerted by the boy will be larger, and therefore the side of the boy will tilt downward.
Answer: A is your answer i am sorry if i am wrong
Explanation:
he first PLCs were programmed with a technique that was based on relay logic wiring schematics. This eliminated the need to teach the electricians, technicians and engineers how to program a computer - but, this method has stuck and it is the most common technique for programming PLCs today.
Answer:
From question (a) and (b) the pendulum motion is perpendicular to the force so the normal force will do no work and the tension in the string of the pendulum will not work

And
so

c
An example will be a where a stone is attached to the end of a string and is made to move in a circular motion while keeping the other end of the string in a fixed position
d
A dog walking along a surface which has friction, here the frictional force would acting in the direction of the motion and this would do positive work
Explanation: