Answer: A (Ft)
Explanation: The impulse experienced by the object equals the change in momentum of the object. In equation form, F • t = m • Δ v
Displacement is the final position of the object minus the initial position of the object.
Xf - Xi. Displacement is not the distance of the object. If you go to the right 10m and to the left another 10m, your displacement is 0m. But your distance is 20m
First, you find what 20% of 10 gallons of gas would be. This will show how many gallons the car actually uses.
10 gallons x 20% =
10 x 0.20 =
2 gallons used
Then you subtract that number from the total 10 gallons to get how many gallons of gas would be wasted.
10 gallons - 2 gallons =
8 gallons of gas wasted
B, air blowing from across the field is as a bullet fired from a rifle
To solve the two parts of this problem, we will begin by considering the expressions given for gravitational potential energy and finally kinetic energy (to find velocity). From the potential energy we will obtain its derivative that is equivalent to the Force of gravitational attraction. We will start considering that all the points on the ring are same distance:

Then the potential energy is

PART A) The force is excepted to be along x-axis.
Therefore we take a derivative of U with respect to x.



This expression is the resultant magnitude of the Force F.
PART B) The magnitude of loss in potential energy as the particle falls to the center

According to conservation of energy,

