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Plz help, and show work
1. A penguin falls off a 35m cliff onto the head of a napping polar bear. The penguin starts from rest and accelerates due to gravity (9.8m/s2). How long does the penguin fall? (your final answer should be positive)


2. A penguin flees a cranky polar bear. The penguin starts from rest and runs at a constant acceleration east. At 20 seconds the penguin is running at a velocity of 2m/s. What is the acceleration of the penguin?

Respuesta :

1.
Given:
S=-35m(downward), a=-9.8m/s2, u=0(start from rest)

Solution:
Formula: S=ut+(1/2)(a)(t^2)
-35m=(0)t+(1/2)(-9.8m/s)(t^2)
t^2= 7.142857
t= 2.67s

Answer: t=2.67s


2.
Given:
u=0(start from rest), t=20s, v=2m/s

Solution:
Formula: v=u+at
2m/s=0+a(20s)
a=0.1m/s^2

Answer: a=0.1m/s^2

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