<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
.012 J is going to be your answer
The acceleration of gravity is inversely proportional to
the square of the distance from Earth's center.
The acceleration of gravity is 9.8 m/s² on the Earth's surface ...
6380 km from the center.
If the acceleration of gravity at 'h' is 4.9 m/s² ... 1/2 of what it is
on the surface, then the distance from the center is
(6380 x √2) = 9,023 km (rounded) ,
and 'h' is the distance above the surface
= (9,023 - 6,380) = 2,643 km (rounded) .
