A :-) for this question , we should apply 
a = v - u by t 
Given - u = 4.77 m/s 
 v = 23.5 m/s 
 t = 5.18 m/s 
Solution - 
a = v - u by t 
a = 23.5 - 4.77
a = 28.27 m/s^2 
.:. The acceleration is 28.27 m/s^2
        
             
        
        
        
Answer:
The first frequency of audible sound in the speed sound is 
f = 662 Hz
Explanation:
vs = 344 m/s
x =  52 cm * 1 / 100m = 0.52m
The wave length is the distance between the peak and peak so 
d = 2x
d = 2*0.52 m
d = 1.04 m 
So the frequency in the speed velocity is 
f = 1 / T 
f = vs / x = 344 m/s / 0.52m
f ≅ 662 Hz
 
        
             
        
        
        
Answer:
The time taken to stop the box equals 1.33 seconds.
Explanation:
Since frictional force always acts opposite to the motion of the box we can find the acceleration that the force produces using newton's second law of motion as shown below:

Given mass of box = 5.0 kg
Frictional force = 30 N
thus

Now to find the time that the box requires to stop can be calculated by first equation of kinematics 
The box will stop when it's final velocity becomes zero 

Here acceleration is taken as negative since it opposes the motion of the box since frictional force always opposes motion.
 
        
             
        
        
        
Answer:
5.56 A
Explanation:
From the question,
Q = it.............. Equation 1
Where Q = charges, i = current, t = time.
Make i the subject of the equation
i = Q/t.............. Equation 2
Given: Q = 200 coulombs, t = 0.6 minutes = (0.6×60) seconds
Substitite these values into equation 2
i = 200/(0.6×60)
i = 5.56 A
Hence the magnitude of the current flowing through the circuit is 5.56 A
 
        
             
        
        
        
The height difference is found by

Then the change in potential energy is
