Answer:
a

b

c

Explanation:
From the question we are told that
The mass of the bag is 
The normal force experienced is 
The maximum acceleration of the bag is 
Generally this normal force experience by the bag is mathematically represented as

=> 
=> 
=> ![\theta = cos^{-1}[0.9183]](https://tex.z-dn.net/?f=%5Ctheta%20%20%3D%20cos%5E%7B-1%7D%5B0.9183%5D)
=> 
Generally for the bag not to slip , it means that the frictional force is equal to the sliding force

Hence
is mathematically represented as
While
is mathematically represented as

So
=>
=> 
Generally from the workdone equation we have that

Here
is the work done by friction which is mathematically represented as
Here s is the distance covered by the bag
is zero given that velocity at rest is zero
and

so

=> 
substituting 2.55 m/s for v_i and 0.350 for \mu_k we have that

=> 
Answer:
The correct option is D
Explanation:
This question can be better understood when discussed using the Newton's first law of motion which states that an object would continue to move with a uniform speed (in a straight line) unless acted upon by an external force. What happens here (in the question) is that the bike rider would have continued moving at a constant speed (to the right) if not for the opposing force of the wind that acted against her (to the left). <u>This wind/force would cause her speed to reduce or slow down (as posited by the law)</u>.
Answer:
A police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase.
Explanation:
In Physics, Doppler effect can be defined as the change in frequency of a wave with respect to an observer in motion and moving relative to the source of the wave.
Simply stated, Doppler effect is the change in wave frequency as a result of the relative motion existing between a wave source and its observer.
The term "Doppler effect" was named after an Austrian mathematician and physicist known as Christian Johann Doppler while studying the starlight in relation to the movement of stars.
<em>The phenomenon of Doppler effects is generally applicable to both sound and light. </em>
An example of the Doppler effect is a police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase. This is so because when a sound object moves towards you, its sound waves frequency increases, thereby causing a higher pitch. However, if the sound object is moving away from the observer, it's sound waves frequency decreases and thus resulting in a lower pitch.
<em>Other fields were the Doppler effects are applied are; astronomy, flow management, vibration measurement, radars, satellite communications etc. </em>
Answer:
The fractional kinetic energy will be lost if the collision is inelastic. In inelastic collision, the kinetic energy is converted into other forms of energy.
The lost energy became heat and sound energy.
Explanation:
During inelastic collision, the kinetic energy of a moving object does not conserve. It changes into another form of energy such as sound energy and heat energy etc.
For example, when a moving car hit another car or wall etc, the kinetic energy is converted into sound and heat energy. This type of collision is inelastic collision.