A police officer uses a radar gun to determine the speed of a car. A specialized radar gun uses ultraviolet light to determine t
2 answers:
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Answer:
2940.1 joules would you burn in climbing stairs all day.
Explanation:
Work = W = F d
going up stairs would be against force of gravity
W = mgh
where h is the height
the question is not complete because we need speed or distance
h = v t
so assuming 1 step per second
h = 86,400 steps 7inchs/step
0.0254 m/inch
h = 15362 m
so from this
W = 800 N 15362
= 12289600 J
that means YOU need 12289600 J to walk 1 step per second all day
divide that by 4180 J /Kcal
Kcal =
=
= 2940.1 Kcal
if you ran faster you would use more energy 2 steps per second would mean 5880 Kcal.
Answer:
The center of mass of the two-ball system is 7.05 m above ground.
Explanation:
<u>Motion of 0.50 kg ball:</u>
Initial speed, u = 0 m/s
Time = 2 s
Acceleration = 9.81 m/s²
Initial height = 25 m
Substituting in equation s = ut + 0.5 at²
s = 0 x 2 + 0.5 x 9.81 x 2² = 19.62 m
Height above ground = 25 - 19.62 = 5.38 m
<u>Motion of 0.25 kg ball:</u>
Initial speed, u = 15 m/s
Time = 2 s
Acceleration = -9.81 m/s²
Substituting in equation s = ut + 0.5 at²
s = 15 x 2 - 0.5 x 9.81 x 2² = 10.38 m
Height above ground = 10.38 m
We have equation for center of gravity
m₁ = 0.50 kg
x₁ = 5.38 m
m₂ = 0.25 kg
x₂ = 10.38 m
Substituting
The center of mass of the two-ball system is 7.05 m above ground.