Question: A 60-kg woman leaps vertically from a crouching position in which her center of mass is 30 cm above the ground. As her feet leave the floor her center of mass is 62 cm above the ground; it rises to 105 cm at the top of her leap. - What average force was exerted on her by the ground during the jump? - What maximum s
Question: The blades of a fan running at low speed turn at 250 rpm. When the fan is switched to high speed, the rotation rate increases uniformly to 350 rpm in 5.75 s. a.) What is the magnitude of the angular acceleration of the blades? b.) How many revolutions do the blades go through while the fan is accelerating?
Question: A rotating cylinder about 16 km in length and 8.0 km in diameter, is designed to be used as a space colony. With what angular speed must it rotate so that the residents on it will experience the same acceleration due to gravity on Earth?
A rock is thrown upward from ground level with initial velocity Vo, beside a building whose roof height is H. In terms of Vo, H and g, find what percent of its total flight time the rock is above the roofline.
Question: Bar BDE is attached to two links AB and CD. Knowing that at the instant shown link AB rotates with a constant angular velocity of 3 rad/s clockwise, determine the acceleration (a) of point D, (b) of point E. Please refer to attachment to see a diagram of this scenario.
A 12.0-kg box rests on the flat floor of a truck. The coefficients of friction between the box and the floor are s=0.19 and k=0.15. The truck stops at a stop sign, and then begins to move with an acceleration of 2.20 m/s^2 . If the box is 1.80 m from the rear of the truck when the truck starts, (a) How much tim
A flywheel whose diameter D= 1.2 m, is initially rotating at Wo= 200 revolutions per minute. During time t- 60 sec, its rotation rate increases with constant acceleration to a final value of Wf= 1000 rev/min. Part a. find the initial tangential speed in m/sec, of a point on the rim. Part b. find the angular acceleration in ra
I need help with the following two questions. Please view the attachments to see the questions.
A 500-kg helicopter ascends from the ground with an acceleration of 2.00m/s^2. Over a 5.00 seconds interval, what is (a) the work done by lifting force, (b) the work done by the gravitational force, and (c) the new work done on the helicopter?
Cam mechanisms are used in many machines. For example, cams open and close the valves in your car engine to admit gasoline vapor to each cylinder and to allow the escape of exhaust. The sliding wedge duplicates the function of a rotating eccentric disk on a camshaft of your car. Assume there is no friction between the wedge and
A test rocket is fired vertically from a well. A catapult boosts it to ground level, where it has a vertical velocity of 60.0 m/s. At ground level, the rocket engine fires, and the rocket accelerate upward with an acceleration of 5.00 m/s2. When the rocket is 800 m above the ground the engine fails, and the rocket goes into fr
Please see the attachment. What is the most straight forward way to solve it? Please provide explanations for the major steps. Thanks.
The position of a particle which moves along a straight line is defined by: x=t^3-6t^2-15t+40, where x is in feet and t is in seconds. Determine the time at which the velocity will be zero, the position and distance traveled at that time, and the acceleration of the particle at that time.
To protect his food from hungry bears, a boy scout raises his food pack with a rope that is thrown over a tree limb at height h above his hands. He walks away from the vertical rope with a constant velocity, vboy, holding the free end of the rope in his hands. a) Show that the speed v of the food pack is given by x(x^2+h^2)^(-1
A 1000 newton crate is being pushed across a level floor at a constant speed by a force of 300 newtons at an angle of 20 degrees below the horizontal A-what is the coeffecient of kinetic friction between the crate and the floor. B-if the 300 newton force is instead of pulling the block at an angle of 20 degrees above the hori
A uniform, solid cylinder with mass M and radius 2R rests on a horizontal tabletop. A string is attached by a yoke to a frictionless axle through the center of the cylinder so that the cylinder can rotate about the axle. The string runs over a disk shaped pulley with mass M and radis R that is mounted on a frictionless axle th
Atwoods Machine Two blocks, A and B are attached to each end of a cord attached to a pulley C. Block A hangs slightly higher than Block B. Find the linear accelerations of block A and B, and the angular acceleration of the wheel C and the tension in each side of the cord if there is no slipping between the cord and the surf
A centrifuge is used for training astronaunts to withstand large accelerations. It consists of a chamber (in which the astronaunt sits) that is fixed to the end of a long horizontal and rigid pole. The arrangement is rotated about an axis perpendicular to the pole's free end. Such a centrifuge starts from rest and has an angular
A Ferris wheel rotates at an angular velocity of 0.24 rad/s. Starting from rest, it reaches its operating speed with an average angular acceleration of 0.030 rad/s^2. How long does it take the wheel to come up to operating speed?
In a pulley system, the time of descent of a 100 gram mass is found to be 35 seconds. The vertical distance is given as 120 cms. The radius of the pulley (in the form of a disc) is 5 cms. Mass of the pulley is unknown. Determine (a) angular acceleration of the pulley (b) number of revolutions it makes during this time (c) To
A 2500 kg car traveling to the north is slowed down uniformly from an initial velocity of 20.0 m/s by a 6250 N braking force acting opposite the car's motion. Use the impulse-momentum theorem to answer the following questions: a. What is the car's velocity after 2.50 s? b. How far does the car move during 2.50 s? c. How
A cylindrical fishing reel has a moment of inertia of I = 6.81Ã ?10-4 kg* m2 and a radius of 3.13 cm. A friction clutch in the reel exerts a restraining torque of 1.49 N*m if a fish pulls on the line. The fisherman gets a bite, and the reel begins to spin with an angular acceleration of 63.7 rad/s2. 1) What is the force of t
See attached file for diagram. A uniform rod of mass M = 5.18 kg and length L = 1.20 m can pivot freely (i.e., we ignore friction) about a hinge attached to a wall, as seen in the figure attached in a Word doc. The rod is held horizontally and then released. Determine the angular acceleration of the rod at the moment of relea
A boat has a mass of 6800 kg. Its engine generates a drive force of 4100 N, due west, while the wind exerts a force of 800 N, due east, and the water exerts a resistive force of 1200 N due east. What is the magnitude and direction of the boat's acceleration?
A boat has a mass of 6800 kg. Its engines generate a drive force of 4100 N, due west,while the wind exerts a force of 800 N, due east, and the water exerts a resistive force of 1200 N due east. What is the magnitude and direction of the boats acceleration?
A disk starts from rest and accelerates at constant angular acceleration to 10 rev/sec in time t. While rotating through the next 60 revolutions, its speed increases to 15 rev/sec. Part a. Find the angular acceleration in rad/sec^2. Part b. Find T, the time required from 10 to 15 rev/sec.
A child stands on the surface of a frozen pond 12 m from the shore. If the coefficient of static friction between her boots and the ice is 0.05, A. Determine the minimum time required for the child to walk to shore without slipping.
A mass attached to a 59.7 cm long string starts from rest and is rotated 32 times in 68.0 s before reaching a final angular speed. Determine the angular acceleration of the mass, assuming that it is constant.
Q: "The blades in a blender rotate at a rate of 7290 rpm. When the motor is turned off during operation, the blades slow to rest in 3.67 s. What is the angular acceleration as the blades slow down? The initial rotation is in the positive direction." The OTA's solution is attached. We both got an answer of 208 rad/s^2.
A gun is fired vertically into a m = 1.34 kg block of wood at rest on a thin horizontal sheet directly above it, as shown in the attached figure (Word file). If the bullet has a mass of 22.0 g and strikes the block with speed v = 300 m/s, how high will the block rise into the air after the bullet becomes embedded in it?