<span>When an object travels in a curved path, there must be a force acting toward the center of the circular trajectory. This force is called "centripetal force", and it cause an acceleration of the object, called "centripetal acceleration". The effect of this acceleration is that the velocity of the object changes in direction: however if the circular motion is uniform, the speed (=the magnitude of the velocity) does not change. In this case, the magnitude of the centripetal force is given by 
</span>

<span>
where m is the mass of the object, v its velocity, and r the radius of the circular path.</span>
 
        
             
        
        
        
Answer:
B
Explanation:
The correct answer is B) have unlike charges. Since they are attracted to each other they have to be unlike
 
        
             
        
        
        
From the average speed you can fix an equation:
Average speed = distance / time
You know the average speed = 65.1 kg / h, then 
65.1 = distance / total time,
where total time is the time traveling plus 22.0 minutes
Call t the time treavelling and pass 22 minutes to hours:
65.1 = distance / [t + 22/60] ==> distance = [t + 22/60]*65.1
 
From the constant speed, you can fix a second equation
Constant speed = distance / time traveling
94.5 = distance / t ==> distance = 94.5 * t
The distance is the same in both equations, then you have:
[t +22/60] * 65.1 = 94.5 t
Now you can solve for t.
65.1t + 22*65.1/60 = 94.5t
94.5t - 65.1t = 22*65.1/60
29.4t = 23.87
t = 23.87 / 29.4
t  = 0.812 hours
distance = 94.5 km/h * 0.812 h = 76.7 km
Answers: 1) 0.81 hours, 2) 76.7 km 
        
             
        
        
        
Answer:
0.426 L
Explanation:
Boyles law is expressed as p1v1=p2v2 where 
P1 is first pressure, v1 is first volume
P2 is second pressure, v2 is second volume.
Given information
P1=96 kPa, v1=0.45 l
P2=101.3 kpa
Unknown is v2
Making v2 the subject from Boyle's law

Substituting the given values then

Therefore, the volume is approximately 0.426 L
 
        
             
        
        
        
According to Charles law, we know, at constant pressure, volume is directly proportional to temperature. 
So, <span>V/T = constant 
</span>
V₁/t₁ = V₂/t₂
V₁t₂ = V₂t₁
Here, we have: V₁ = 9 mL
V₂ = ?
T₂ = 50+272 = 323 K
T₁ = 19+273 = 292 K
Substitute their values into the expression:
9 × 323 = V₂ × 292
V₂ = 2907 / 292
V₂ = 9.95
After rounding-off to unit place value, it would be equal to 10 mL
So, In short Option C would be your correct answer.
Hope this helps!