<span>Similar fossils found on different continents helped geologists determine how the continents used to be connected. Mountain belts marked the boundaries of moving plates, which showed in which direction the different continents drifted. Extrapolating from this information, scientists had a rough idea of how the continents were arranged eons ago.</span>
Answer:
a) 4.49Hz
b) 0.536kg
c) 2.57s
Explanation:
This problem can be solved by using the equation for he position and velocity of an object in a mass-string system:

for some time t you have:
x=0.134m
v=-12.1m/s
a=-107m/s^2
If you divide the first equation and the third equation, you can calculate w:

with this value you can compute the frequency:
a)

b)
the mass of the block is given by the formula:

c) to find the amplitude of the motion you need to know the time t. This can computed by dividing the equation for v with the equation for x and taking the arctan:

Finally, the amplitude is:

Your answer should be 9.7 :)
Answer:
Work done W =1406.25 J
Explanation:
Work done on a body can be calculated using newton's 2nd laws:
F=ma
Hence acceleration of the block is given by:
Displacement of the object is given by:

Substitute the values
Now work done is given by:
W=F.S
W = 25×56.25
W =1406.25 J