<u>Answer</u>
The acceleration is
to the nearest tenth
<u>Explanation</u>
Since the car was travelling at 
before it starts to decelerate, the initial velocity is
.
The final velocity is 
, because the car came to a stop.
The time taken is 
.
Using the Newton's equation of linear motion,
, we find the acceleration by substituting the known values.
This implies that,
This gives us,
We divide both sides by 15 to get,
or
To solve this you must set up what is called a proportion. A proportion is a way of comparing two comparing values where one of the four values is missing. In your problem the missing value is the height of the smallest tree in the model.
To set up a proportion, you need all of your values. The easiest way to do this is to list them:
Highest tree in real life: 40ft
Highest tree in model: 10ft
Smallest tree in real life: 4ft
Smallest tree in model: x
So know you can set your proportion like this:
40/4 = 4/x
(When setting up a proportion, you always want to have the values belong to each other. For example don't put the height of the small tree in the model underneath the value of the highest tree in real life.)
So know to find what the x values equals, we need to cross multiply. And then all that's left after that is to solve for x.
40 times x = 4 times 4
40x = 16
x = 2.5
The smallest tree in the model should equal 2.5 feet.
Hope this helps! :)
W=mgh W=(20)(9.8)(1) w=196J
Gravity affects weight of an object
Its weight reduces as it moves away from the center as gravity is strongest near the core and reduces as you move away
Hope this helps C:
B. so light can shine through it from below.
