Forces occur in pairs and can be either balanced or unbalanced. Balanced forces do not cause a change in motion. Unbalanced Forces do cause a change in motion.
The speed of the car at the top of the hill is 14m/s
<u>Explanation:</u>
given that
Initial velocity u of the car=0 m/s
The distance can be determined by finding out the difference between the elevation of the first slope and second slope.
elevation of the first slope=26 m
elevation of second slope=16m
distance s=26-16=10 m
acceleration due to gravity g=9.8 m/s2
speed of the car at the top of the hill can be determined by using the equation

speed of the car at the top of the hill is 14m/s
A because water has more volume when it's warmer