A constant 12.0-N net force acts for 3.0son a 3.0-kg object. What is the object's change of velocity? 12 m/s 4 m/s O 3 m/s e 5 m/s

Jacob, a professional heavyweight boxer, delivers a forceful punch with his fist and arm, combining for an effective punching mass of 2.56 kg. His fist strikes a heavy bag at a velocity of 9.1 m/s and comes to a halt 10.9 ms after initial contact. Determine the magnitude of the average net force that Jacob exerts on the heavy bag. a. 2137 N b. 3569 N c. 5321 N d. 2757 Ne. 6112 N

lower a crate of mass ?1=5.00 kgm1=5.00 kg to the bottom of a steep ravine of height ?=25.0 mH=25.0 m. The crewman of mass ?2=55.6 kgm2=55.6 kg is walking while holding the rope, being careful to lower the crate at a constant speed of ?0=1.50 m/sv0=1.50 m/s. Unfortunately, when the crate reaches a point ℎ=13.9 mh=13.9 m above the ground, the crewman steps on a slick patch of ice and slips. The crate immediately accelerates toward the ground, dragging the hapless crewman across the ice and toward the edge of the cliff. Assuming the ice is perfectly slick, so that there is no friction between the crewman and the ice once he slips and falls down, at what speed ?1v1 will the crate hit the ground? Assume also that the rope is long enough to allow the crate to hit the ground before the crewman slides over the side of the cliff, and that the pulley is frictionless. ?1

öaalg äbäi A horizontal force of 1.5 N acts on a 0.2kg mass to accelerate it along a horizontal path. How fast is the mass going after acceleration from rest through 0.3 m? Neglect the *.friction 2.1 m/sec 3.66 m/sec 2.54 m/sec

A cat kicks a 0.43 kg chees block that was initially at rest. the net force is 20. What is the cheeses speed at t= 20 ms

During an autumn storm, a 0.012 kg hail stone travelling at 20.0 m/s made a 0.20 cm deep dent in the hood of Casey’s new car. What average force did the car exert to stop the damaging hail stone? *Use g=9.8 a. 240 N b. 86 N c. 120 N d. 48 N e. 521 N

A1500 kg car was moving +31 (E) in the exit lane, but 7.0 s later only +10 "/ (E) at the exit ramp. a) what was the car's average acceleration during that interval? +20.5 m/ s² (E) +21 m/s (E) -21 m/s (W) +3 m/g² (E) +5.86 "/g² (E) -3 "/s² (W) m

Vmax In a laboratory experiment, a sphere of diameter 8.0 mm is released from rest at t = 0 at the surface of honey in a jar, and the sphere's downward speed v when it travels in the honey is found to be given by v = Vmax (1 - e-t/T), where 0.040 m/s and T = 0.50 s. (a) Obtain an expression for a(t). (b) Draw graphs for v(t) and a(t) for the time interval 0 to 2.0 s. (c) Obtain an expression for x(t), choosing the positive x axis as downward, and draw the graph for this func- tion. (d) Use your x(t) graph to determine the time interval needed for the sphere to reach the bottom of the container if the surface of the honey is 0.10 m above the bottom of the jar. ... =

WE-4 A 3.00kg block is initially sliding to the right on P (N) 20 a frictionless surface at 7.00m/s. Force P is directed to the left and is applied to the block continuously starting at the initial position as shown below. The magnitude of P varies as shown in the graph to the right. V=7.00m/s 15 10 5. 0 1 2 3 4 (m) a) Find the magnitude of the work done by the force P as the block moves from x-0 to x=4m. b) Find the kinetic encrgy of the block at x-4m. Neglect air resistance (and the surface is frictionless). c) Find the speed of the block at x-4m. P Type here to search %23 直

2. A6.0-kg block initially at rest is pulled to the right along a horizontal, frictionless surface by a constant horizontal force of 12 N. Find the block's speed after it has moved 3.0m.