Answer:
Δt = 5.29 x 10⁻⁴ s = 0.529 ms
Explanation:
The simple formula of the distance covered in uniform motion can be used to find the interval between when the sound arrives at the right ear and the sound arrives at the left ear.

where,
Δt = required time interval = ?
Δs = distance between ears = 18 cm = 0.18 m
v = speed of sound = 340 m/s
Therefore,

<u>Δt = 5.29 x 10⁻⁴ s = 0.529 ms</u>
21. light changes its direction when travelling through a new medium because denser mediums have a higher angle of refraction.
Answer:
<em>1.228 x </em>
<em> mm </em>
<em></em>
Explanation:
diameter of aluminium bar D = 40 mm
diameter of hole d = 30 mm
compressive Load F = 180 kN = 180 x
N
modulus of elasticity E = 85 GN/m^2 = 85 x
Pa
length of bar L = 600 mm
length of hole = 100 mm
true length of bar = 600 - 100 = 500 mm
area of the bar A =
=
= 1256.8 mm^2
area of hole a =
=
= 549.85 mm^2
Total contraction of the bar =
total contraction =
==>
= <em>1.228 x </em>
<em> mm </em>
Newton's three laws of motion can be used to describe the motion of the ice skating.
<h3>Newton's first law of motion</h3>
Newton's first law of motion states that an object at rest or uniform motion in a straight line will continue in that state unless it is acted upon by an external force.
- Based on this law, once the ice skating starts, it will continue endlessly unless external force stops it.
<h3>Newton's second law of motion</h3>
Newton's second law of motion states that the force applied to an object is directly proportional to the product of mass and acceleration of an object.
- Based on this law, the force applied to the ice skating is equal to the product of mass and acceleration of the ice skating.
<h3>Newton's third law of motion</h3>
This law states that action and reaction are equal and opposite.
- Based on this law, the force applied to the ice skating is equal in magnitude to the reaction of ice.
Learn more about Newton's law here: brainly.com/question/3999427
Inertia is the resistance of an object to a change in its B. Motion