Answer:
3.258 m/s
Explanation:
k = Spring constant = 263 N/m (Assumed, as it is not given)
x = Displacement of spring = 0.7 m (Assumed, as it is not given)
= Coefficient of friction = 0.4
Energy stored in spring is given by
As the energy in the system is conserved we have
The speed of the 8 kg block just before collision is 3.258 m/s
Answer:
Tension in the string at this position: 3.1 N.
Explanation:
Convert the radius of the circle to meters:
.
What's the net force on the object?
The object is in a circular motion. As a result,
,
where
is the net force on the object,
is the mass of the object, 
is the velocity of the object, and
is the radius of the circular motion.
For this object,
.
The output unit of net force should be standard if the unit for mass, velocity, and radius are all standard. The net force shall always point towards the center. In this case the net force points downwards.
What are the forces on this object?
There are two forces on the object at this moment:
- Weight,
, which points downwards. 
. - Tension,
, which also points downwards. The size of the tension force needs to be found.
What's the size of the tension force?
Gravity and tension points in the same direction. The size of their resultant force is the sum of the two forces. In other words,
.
.
All three values in this question are given with two sig. fig. Round the value of to the same number of significant figures.
<h3><u>Answer;</u></h3>
<em>B. Sound waves can move through various mediums.</em>
<h3><u>Explanation;</u></h3>
- <em><u>A wave is a transmission of a disturbance from one point to another</u></em>. It involves transmission of energy from the source to another point.
- <u><em>A wave may or may not require a medium for transmission.</em></u> Waves that require medium for transmission are called <em><u>mechanical waves </u></em>and those that do not require medium for transmission are known as <em><u>electromagnetic waves</u></em>.
- <em><u>Light is an example of electromagnetic wave therefore it can be blocked when obstacles are placed on its path.</u></em> However, for the case of sound waves, they can not be blocked by an obstacle as sound would travel through the medium used to block.
Answer:
red shift, indicating that the universe is expanding
Explanation:
Doppler effect occurs when a source of a wave (e.g. light, or sound waves) moves relative to an observer; as a result of this relative motion, the wavelength of the wave appears lengthened/shortened to the observer. Two situations can occur:
- The source of the wave is moving towards the observer - in this case, the wavelength of the wave becomes shorter. If the wave is visible light, such as the light emitted by distant galaxies, this means that the wavelength of the light shifts towards the blue-end of the spectrum (blue-shift)
- The source of the wave is moving away from the observer - in this case, the wavelength of the wave becomes longer. If the wave is visible light, such as the light emitted by distant galaxies, this means that the wavelength of the light shifts towards the red-end of the spectrum (red-shift)
In our universe, we observe a red-shift for all the distant galaxies: this means that these galaxies are moving away from us, so this is an indication that the universe is expanding.
Answer:
option (a)
Explanation:
There are some properties of charge given as
(a) Charges are of two types: negative charge and positive charge.
(b) Like charges repel each other and unlike charges attract each other.
(c) charges are conserved in nature.
(d) charges are quarantined.
So, the two charges which are opposite in nature can only attract each other.
So, if there is one negative and one positive charge, they always attract each other.
The force of attraction or repulsion between the two charges is given by the Coulomb's law.
