1) A crate moves 10 m to the right on a horizontal surface as a woman pulls on it with a 10-N force.
Rank the situations shown below according to the work done by her force, least to greatest.
a. 1, 2, 3b. 2, 1, 3c. 2, 3, 1d. 3, 2, 1
2) What is the kinetic energy of a 0.135-kg baseball thrown at 40.0 m/s?
a. 54.0 J
b. 87.0 J
c. 108 J
d. 216 J
3) Use the work-energy theorem to find the force required to accelerate an object (m = 1 kg) moving
along the x axis from 4 m/s to 10 m/s in a distance of 6 m.
- a.9 N
- b.15 N
- c.7 N
- d.12 N
4) Problem (2 points)
Three forces, F1 = 20.0 N, F2 = 40.0 N, and F3 = 10.0 N act on an object with a mass of 2.00 kg which can move
along a frictionless inclined plane as shown in the figure. The questions refer to the instant when the object has
moved through
a distance of 0.600 m along the surface of the inclined plane in the upward direction. Calculate the amount of work
done by
(a) F1
(b) F2
(c) F3
5) Fluid fills the container shown in the figure. At which of the indicated points is the pressure greatest?
A) A
B) B
C) C
D) D
E) The pressure is the same at each of the labeled points.
6) As the speed of a moving fluid increases, the pressure in the fluid
A) increases.
B) remains constant.
C) decreases.
D) may increase or decrease, depending on the density of the fluid.
7) The drawing shows a blood transfusion procedure. 800 g of blood (ρblood = 1060 kg/m3) in a sealed (closed) bag, is fed into the patient via a needle with a 0.5 mm entrance diameter and 0.3 mm exit diameter. Assume the venous gauge pressure (pressure at tip of needle) is 1900 Pa, and
the bag should be completely empty in 1 hour. Calculate:
(1) The volume flow rate
(2) Speed of the blood at needle entrance (v2) and exit (v1)
(3) Assuming the blood is static between the bag and needle, use Bernoulli's equation to calculate the height of the bag (h).