Aforce with magnitude (5.00n/m2)x2 and directed at a constant angle of 31.0◦ with the +x-axis acts on an object of mass 0.250 kg as the object moves parallel to the x-axis. there are no other forces on the object that have components parallel to the x-axis. how fast is the object moving at x = 1.50 m if it has a speed of 4.00 m/s at x = 1.00 m?

6.57 m/s

Explanation:

From work energy theorem, work done = W = Change in Kinetic energy

W =

here v is the final velocity and u is the initial velocity and F is the force.

Horizontal component of the force is considered here since motion is along the horizontal (X) direction. So cos 31

Work done =

⇒ =3.39 J

= 3.39

⇒ = 3.30

⇒ Speed at x = 1.50 m = v = 6.57 m/s

b.

explanation:

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.