The correct answer should be <span>A. If you see a wear bar across the width of the tread, it's time to change the tire
This is an incorrect sentence because you should change a tire before you see the wear bar. At the time you see the bar, you should've already changed it. </span>
Explanation:
When a constant force acts upon an object the acceleration of the object varies inversely with its mass.
or
If m₁ = 21 kg, a₁ = 3 m/s², m₂ = 9 kg
We need to find a₂
So,
So, if mass is 9 kg, its acceleration is 7 m/s².
<u>Answer:</u>
The spinning of the earth around its own axis causes day and night.
<u>Explanation:</u>
Earth has two types of motions. It spins around its own axis causing day and night every 12 hours and completes a rotation in 23.93 hours that make a full day. The part of the earth that faces sunlight during spinning experiences day and the other part has night. It also rotates around the sun and completes one rotation in 365 days that makes a year.
Think of it this way: If you test only one variable then you know that the difference in the experimental and control setup is that one independent variable. If you test more than one you will not know which one made the difference. Hope this helps :)
