Problem 1
Answer: Approximately 1.3 m/s^2
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Work Shown:
We'll use the formula F = m*a, which is from Newton's second law.
The force applied is F = 89 newtons. The mass of the boulder is m = 69 kilograms. This means,
F = ma
89 = 69*a
a = 89/69
a = 1.28985507246377
a = 1.3
I rounded to 2 sig figs because the other given values (89 and 69) are to 2 sig figs as well.
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Problem 2
Answer: Approximately 0.53 m/s^2
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Work Shown:
We'll follow the same idea as problem 1
This time we are given F = 45 and m = 85
So,
F = ma
45 = 85*a
85a = 45
a = 45/85
a = 0.52941176470589
a = 0.53
The acceleration is roughly 0.53 m/s^2, which means that for every second, the speed is increasing by roughly 0.53 m/s.