Answer: Sound waves are a waves of compression and rarefaction, by which sound is propagated in an elastic medium such as air.
Explanation:
In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid.
A
point source is to be used with a concave mirror to produce a beam of
parallel light. The source should be placed midway between the center
of curvature and the mirror. To solve this question you have to draw
a ray diagram. Apply the mirror equation to determine the image
distance and finally make sure that the first two steps are
consistent with each other.
<span>I
hope this helps, Regards.</span>
A. Equal and opposite
For every action, there is an equal and opposite reaction
Answer:
The work done by Joel is greater than the work done by Jerry.
Explanation:
Let suppose that forces are parallel or antiparallel to the direction of motion. Given that Joel and Jerry exert constant forces on the object, the definition of work can be simplified as:

Where:
- Work, measured in joules.
- Force exerted on the object, measured in newtons.
- Travelled distance by the object, measured in meters.
During the first 10 minutes, the net work exerted on the object is zero. That is:





In exchange, the net work in the next 5 minutes is the work done by Joel on the object:


Hence, the work done by Joel is greater than the work done by Jerry.
Answer:
4.5 Nm (Anticlockwise)
Explanation:
Let the 75 kg kid is sitting at the left end and the 60 kg kid is sitting on the right end.
Anticlockwise Torque = 75 x 1.5 = 112.5 Nm
clockwise Torque = 60 x 1.8 = 108 Nm
Net torque = Anticlockwise torque - clockwise torque
Net Torque = 112.5 - 108 = 4.5 Nm (Anticlockwise)