Answer:
Ans. B) 22 m/s (the closest to what I have which was 20.16 m/s)
Explanation:
Hi, well, first, we have to find the equations for both, the driver and the van. The first one is moving with constant acceleration (a=-2m/s^2) and the van has no acceletation. Let´s write down both formulas so we can solve this problem.
or by rearanging the drivers equation.
Now that we have this, let´s equal both equations so we can tell the moment in which both cars crashed.
To solve this equation we use the following formulas
Where a=1; b=-28.75; c=154
So we get:
At this point, both answers could seem possible, but let´s find the speed of the driver and see if one of them seems ilogic.
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This means that 21.63s will outcome into a negative speed, for that reason we will not use the value of 21.63s, we use 7.12s and if so, the speed of the driver when he/she hits the van is 20.16m/s, which is closer to answer A).
Best of luck
Explanation:
When water is boiled in the flask . Some portion of it is evaporated out . Now when cork is placed on it and is placed in the ice box . It cools down , by which the pressure inside decreases .
Due to decrease of pressure , the boiling point of water also decreases . Now it can boil at lower temperature . Thus it starts boiling at lower temperature even , when placed in the ice box .
'Doing work' is a way of transferring energy from one object to another, energy is transferred when a force moves through a distance.
If i explain with formula
Work done (J) = Energy transferred (J)
So more energy, more work done bc u transferred more energy to move the object and doing the work. and if you only use a little of energy, the work done also only a little.
The horse's position on the ground at time <em>t</em> is
<em>x</em> = (20 m/s) <em>t</em>
The baboon's height from the ground at time <em>t</em> is
<em>y</em> = 3 m - 1/2 <em>g</em> <em>t</em>²
where <em>g</em> = 9.80 m/s² is the magnitude of the acceleration due to gravity.
The baboon falls and lands on the horse, so that the two animals meet when the baboon's height is 2 m from the ground, which happens after
2 m = 3 m - 1/2 <em>g</em> <em>t</em>²
1/2 <em>g</em> <em>t</em>² = 1 m
<em>t</em>² = (2 m) / (9.80 m/s²)
<em>t</em> ≈ 0.452 s
In this time, the horse reaches the tree, so its distance from it is
(20 m/s) * (0.452 s) ≈ 9.04 m
