Which list of observations is the best evidence of only a chemical change occurring?
1 answer:
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Answer:
Work done, W = 2675.4 J
Given:
mass, m = 70.0 kg
height, H = 3.90 m
Solution:
According to the question, as the person jumps the stairs up, there is an increase in the potential energy of the person which is provided by the work done in climbing the stairs and is given by:
Work done, W = mgH
where
g = acceleration due to gravity =
Answer:
(a)
(b) It won't hit
(c) 110 m
Explanation:
(a) the car velocity is the initial velocity (at rest so 0) plus product of acceleration and time t1
(b) The velocity of the car before the driver begins braking is
The driver brakes hard and come to rest for t2 = 5s. This means the deceleration of the driver during braking process is
We can use the following equation of motion to calculate how far the car has travel since braking to stop
Also the distance from start to where the driver starts braking is
So the total distance from rest to stop is 352 + 88 = 440 m < 550 m so the car won't hit the limb
(c) The distance from the limb to where the car stops is 550 - 440 = 110 m