Answer: 1) a = 9.61m/s² pointing to west.
2) (a) Δv = - 37.9km/s
(b) a = - 6.10⁷km/years
Explanation: Aceleration is the change in velocity over change in time.
1) For the plane:


a = 9.61m/s²
The plane is moving east, so velocity points in that direction. However, it is stopping at the time of 13s, so acceleration's direction is in the opposite direction. Therefore, acceleration points towards west.
2) Total change of velocity:


km/s
The interval is in years, so transforming seconds in years:
v = 
km/years
Calculating acceleration:


Acceleration of an asteroid is a = -6.10⁷km/years .
Answer:
μ = 0.725
Explanation:
This problem refers to Newton's second law.
F = ma
Let's write the equations on each axis
Y Axis
N-W = 0
N = W
N = mg
X axis
F-fr = ma
With the body not started moving its acceleration is zero
F-fr = 0
F = fr
The friction force equation is
fr = μ N
fr = μ m g
Let's replace and calculate
F = μ m g
μ = F / mg
μ = 321 /45.2 9.8
μ = 0.725
The period of a simple pendulum is given by:

where L is the length of the pendulum and

is the gravitational acceleration. As we can see, the period of a simple pendulum depends only on its length.
If the compressor removes 500 j if the 700 the 200 j left would have Ben conducted through the refrigerator/200 j released into the room
I would say 1000c as my answer