For #5 It's helpful to draw a free body diagram so you know which way the forces are acting on the block.
the weight mg is acting downwards, and you need to find the vertical and horizontal components of mg using sin and cosine. so do 15x9.8xsin40 which is the force. Assuming no friction, this is the only force acting on the block, as the forces on the vertical plane cancel out i.e the normal force and weight of the block.
after, just do F=ma And since you know F and m, solve for a.
Answer: Total work done on the block is 3670.5 Joules.
Step by step:
Work done:

With F the force, d the displacement, and theta the angle of action (which is 0 since the block is pushed along the direction of displacement, and cos 0 = 1)

Given:
F = 75 N
m = 31.8 kg
Final velocity 
In order to calculate the Work we need to determine the displacement, or distance the block travels. We can use the information about F and m to first figure out the acceleration:

Now we can determine the displacement from the following formula:

Here, the initial displacement is 0 and initial velocity is also 0 (at rest):

Now we still have "t" as unknown. But we are given one more bit of information from which this can be determined:

(using vf as final velocity, and tf as final time)
So it takes about 6.44 seconds for the block to move. This allows us to finally calculate the displacement:

and the corresponding work:

Answer:
Time period of the osculation will be 2.1371 sec
Explanation:
We have given mass m = (B+25)
And the spring is stretched by (8.5 A )
Here A = 13 and B = 427
So mass m = 427+25 = 452 gram = 0.452 kg
Spring stretched x= 8.5×13 = 110.5 cm
As there is additional streching of spring by 3 cm
So new x = 110.5+3 = 113.5 = 1.135 m
Now we know that force is given by F = mg
And we also know that F = Kx
So 

Now we know that 
So 


Speed =dist./time
=73.4/5
=14.68 km/hr