Forces
A 50-kg crate is being raised upwards by a
rope but is slowing with an acceleration of
3.5 m/s2. What is the magnitude of the force
exerted by the rope on the crate?
315 N
A 100 N force is applied horizontally to a stationary 50 kg object. The surface has a static friction coefficient of 0.5. Does it move? Why not?
No, 245 N > 100 N
A block of mass m = 500 g slides down an incline thathas an inclination angle of 30° with the horizontal.The inclined surface has coefficient of kinetic frictionμK = 0.40. The block moves 3.0 m down the incline. How much work was done by the normal force?
0 J
What is the total amount of energy in the system?
40 N
A 1200-kg car is held in place by a light cable on a very smooth (frictionless) ramp. The cable makes an angle of 31.0 degrees above the surface of the ramp, and the ramp itself rises at 25.0 degrees above the horizontal. What is the tension in the cable?
5798 N
Determine the drag coefficient of a 75 kg skydiver with a projected area of 0.33 m2 and a terminal velocity of 60 m/s. Assume density of air is 1.21 kg/m3
1.22
-44 J
A roller coaster starts from rest at a point 45 m above the bottom of a dip. Neglect friction, what will be the speed of the roller coaster at the top of the next slope, which is 30 m above the bottom of the dip?
17.1 m/s
During a physics experiment, blocks P and Q are placed on a horizontal, frictionless working bench. The masses of the blocks are P = 35 kg and Q = 15 kg respectively. Block P is pushed with a horizontal force of 360 N. Determine the acceleration of the system
7.2 m/s2
8.6 m/s
A traveler pulls on a 25 kg suitcase strap at an angle 36° above the horizontal. If the suitcase started at rest and has a final speed of 4.5 m/s while the suitcase moved a horizontal distance of 7.5 m. Use the work-energy theorem to determine the tension in the strap. Assume frictionless surface.
42 N (or 42.717 N w/o sig figs)
A 200 g block on a frictionless surface is pushed against a spring with spring
constant 500 N/m, compressing the spring by 2.0 cm. When the block is released,
at what speed does it shoot away from the spring?
1 m/s
A 50 kg block slides down a 25° frictionless incline. Assuming it was released from rest, how far does it slide in 1.5 seconds?
4.7m
A ball on a string is swung in a vertical circle at a constant speed, completing four full revolutions per second. Its mass is 0.5 kg. The length of the rope is 1.0 m. What is the tension in the string at the bottom of the swing?
320 N
A variable one-dimensional force is applied to a 40 kg object as shown in the figure. The object was at rest when the force was applied initially, but after being pushed the 6.0 m, the object is moving at 4.5 m/s. Determine the size of Fmax, the peak force applied to the object.
140 N (135 N w/o sig figs)
A 0.9 kg particle travels along an x-axis. Three values are Ua= 15.0 J, Ub=35.0 J, and Uc=45.0 J. The particle is released at x=4.5m with an initial speed of 7.0 m/s, headed in the negative direction. What is the magnitude and direction of the velocity at 3m
+10 N
A half-Atwood machine is shown in the figure. It consists of two blocks, one of which(m1 = 10 kg) is free to move horizontally over a frictionless table, while the other (m2 = 6.0kg) falls vertically. The system is released from rest. What is the acceleration of the system as it falls?
3.68 m/s2
What is the terminal speed for an 83.0 kg skier going down a 43.0 degree snow-covered slope on wooden skis with kinetic friction coefficient 0.060? Assume that the skier is 1.80 m tall and 0.300 m wide. Coefficient of drag is 0.205 and density of air is 1.22 kg/m3. Remember that at terminal velocity, a in x direction is 0 m/s2
62 m/s
A variable force is applied to a 2.0 kg object as shown in the figure. The velocity of the object at x = 0.0 m is 4.0 m/s. If the object has 8.0 J of kinetic energy at the location of x = 4.0 m, what was the maximum value of the force, Fs?
4 N
-669 kJ or -668818.5 J