Percent error is the difference between the measured and known value, divided by the known value, multiplied by 100%.
So first, we take our measured value, .299 cm, minus our known value, .225 cm.
.299 cm - .225 cm=.004 cm
Next, we divide that by our known value

Finally, multiply your answer by 100
.0177777778 x 100= 1.77777778 %
Round to three significant figures, and you're done.
=1.78 % error
The moving car experiences unbalanced forces when applying brakes; when a car is slowing as it reaches a stop light.
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Explanation:
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When the car driver applies brakes to a car in order to stop, an unbalanced force is applied to the car. The speed of car gradually reduces and there’s a decrease in acceleration; a net force acts on it.
Options A and D has a box and a rocket always in a rest position. A car with cruise control is an adaptable speed setting for a vehicle which helps it to maintain a fairly constant speed. Constant velocity gives zero acceleration and hence no considerable unbalanced forces appear.
Answer: There are 20 protons neutrons in the atom
Answer:
The last option
Explanation:
The Bohr model was an attempt to explain atomic hydrogen's spectrum. This was done by establishing energy levels of separate electron orbits in the atom.Thos model was followed by the Schrödinger model.
Answer:
<h2>1.264 × 10²⁴ molecules</h2>
Explanation:
The number of molecules can be found by using the formula
N = n × L
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
N = 2.10 × 6.02 × 10²³
We have the final answer as
<h3>1.264 × 10²⁴ molecules</h3>
Hope this helps you