Answer:
a.
b. 
Explanation:
<u>Given:</u>
- Velocity of the particle, v(t) = 3 cos(mt) = 3 cos (0.5t) .
<h2>
(a):</h2>
The acceleration of the particle at a time is defined as the rate of change of velocity of the particle at that time.

At time t = 3 seconds,

<u>Note</u>:<em> The arguments of the sine is calculated in unit of radian and not in degree.</em>
<h2>
(b):</h2>
 
The velocity of the particle at some is defined as the rate of change of the position of the particle.

For the time interval of 2 seconds,

The term of the left is the displacement of the particle in time interval of 2 seconds, therefore,

It is the displacement of the particle in 2 seconds.
 
        
             
        
        
        
The correct answer is C; Bicycles.
Further Explanation:
In major cities, in the United States, have implemented signal lights specifically designed for bicycle riders. The riders also have their own designated bike lanes in many large cities. Drivers in vehicles, are to give the right of way to people on bicycles.
Bicycle riders are to follow the same laws and laws specifically for the riders or they can face fines and tickets. 
Learn more about bicycle laws at brainly.com/question/8934107
#LearnwithBrainly
 
        
             
        
        
        
Melting, as igneous rock is magma or lava that has cooled and hardened.
        
             
        
        
        
I’m pretty sure u have it right
        
             
        
        
        
<h2>Sorry, But I don't know!!</h2>