Answer:
Explanation:
To solve this problem we use the Hooke's Law:
(1)
F is the Force needed to expand or compress the spring by a distance Δx.
The spring stretches 0.2cm per Newton, in other words:
1N=k*0.2cm ⇒ k=1N/0.2cm=5N/cm
The force applied is due to the weight
We replace in (1):
We solve the equation for m:
Answer:
Concave lenses are used in eyeglasses that correct myopia or nearsightedness.
Answer:
t₁ > t₂
Explanation:
A coin is dropped in a lift. It takes time t₁ to reach the floor when lift is stationary. It takes time t₂ when lift is moving up with constant acceleration. Then t₁ > t₂, t₁ = t₂, t₁ >> t₂ , t₂ > t₁
Solution:
Newton's law of motion is given by:
s = ut + (1/2)gt²;
where s is the the distance covered, u is initial velocity, g is the acceleration due to gravity and t is the time taken.
u = 0 m/s, t₁ is the time to reach ground when the light is stationary and t₂ is the time to reach ground when the lift is moving with a constant acceleration a.
hence:
When stationary:
Hence t₂ < t₁, this means that t₁ > t₂.
In Longitudinal waves, particles of the medium vibrate around their mean positions. Their amplitude of vibration is in the direction of the propagation of the wave. In transverse wave of longitudinal wave, <em>the wavelength is always the distance between two particles which are in the same phase.</em>
If we take pressure waves, (sound waves), we have pressure variations created by sound wave along its path. Pressure is maximum at compression regions and pressure is minimum at rarefaction region. In between the two, pressure of air remains as the pressure when there is no wave.
<em>The wave length is then the distance between two consecutive rarefactions or two consecutive compression regions.</em>
<em>It is also the distance traveled by the wave in one time period.</em> Time period is the time the particles in the medium take to vibrate towards the end, turn back to reach the other end of their oscillation and then reach back their position.
