We are given the following values:
weight w = 240 lb = 1,067.52 N
energy E = 3,000 J
The formula for potential energy is:
E = w h
where h is the height the person has to climb, therefore:
h = 3000 / 1067.52
<span>h = 2.81 m</span>
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<span>Therefore he has to climb 2.81 meters</span>
Answer: 140 m
Explanation:
Let's begin by stating clear that motiont is the change of position of a body at a certain time. So, during this motion, the balloon will have a trajectory and a displacement, being both different:
The<u> trajectory</u> is <u>the path followed by the body, the distance it travelled</u> (is a scalar quantity).
The displacement is <u>the distance in a straight line between the initial and final position</u> (is a vector quantity).
So, according to this, the distance the balloon traveled during the first 45 s (its trajectory) is 140 m.
But, if we talk about displacement, we have to draw a straight line between the initial position of the balloon (point 0) to its final position (point 90 m). Being its displacement 95 m.
Answer:
Sample Response: If temperature and surface area increase, then the time it takes for sodium bicarbonate to completely dissolve will decrease, because increasing both factors increases the rate of a chemical reaction.
Explanation:
An oven mitt is used to take the tray out of the oven because it’s an insulator.
Answer:
I = 4.75 A
Explanation:
To find the current in the wire you use the following relation:
(1)
E: electric field E(t)=0.0004t2−0.0001t+0.0004
ρ: resistivity of the material = 2.75×10−8 ohm-meters
J: current density
The current density is also given by:
(2)
I: current
A: cross area of the wire = π(d/2)^2
d: diameter of the wire = 0.205 cm = 0.00205 m
You replace the equation (2) into the equation (1), and you solve for the current I:
Next, you replace for all variables:
hence, the current in the wire is 4.75A
