Blog

A puck of mass m = 1.60 kg slides in a circle of radius r = 18.0 cm on a frictionless table while attached to a hanging cylinder of mass M = 4.0 kg by a cord through a hole in the table. What speed keeps the cylinder at rest?

A  spring stretches 4.68 cm vertically when a 3.50 kg object is suspended from it.  Find the distance (in cm) the spring stretches if you replace the 3.50 kg object with a 4.40 kg object. Assume that the spring obeys the Hook’s law.

During spring semester at MIT, residents of the parallel buildings of the East Campus dorms battle one another with large catapults that are made with surgical hose mounted on a window frame. A balloon filled with dyed water is placed in a pouch attached to the hose, which is then stretched through the width of the room. Assume that the stretching of the hose obeys Hooke’s law with a spring constant of 150 N/m. If the hose is stretched by 3.90 m and then released, how much work does the force from the hose do on the balloon in the pouch by the time the hose reaches its relaxed length?

A puck of mass m = 1.60 kg slides in a circle of radius r = 18.0 cm on a frictionless table while attached to a hanging cylinder of mass M = 8.0 kg by a cord through a hole in the table. What speed keeps the cylinder at rest?

A puck of mass m = 1.60 kg slides in a circle of radius r = 18.0 cm on a frictionless table while attached to a hanging cylinder of mass M = 2.0 kg by a cord through a hole in the table. What speed keeps the cylinder at rest?

A puck of mass m = 1.60 kg slides in a circle of radius r = 18.0 cm on a frictionless table while attached to a hanging cylinder of mass M = 7.0 kg by a cord through a hole in the table. What speed keeps the cylinder at rest?

A circular-motion addict of mass 30.0 kg rides a Ferris wheel around in a vertical circle of radius 12.0 m at a constant speed of 6.0 m/s. What is the magnitude of the normal force on the addict from the seat when both go through the highest point of the circular path?

A block of mass m = 3.60 kg is dropped from height h = 67.0 cm onto a spring of spring constant k = 2490 N/m (see the figure). Find the maximum distance the spring is compressed.  

How fast must a 1.65-g ping-pong ball move in order to have the same kinetic energy as a 145 g baseball moving at 45.5 m/s?

A person pushes a 50.5kg block of ice  at an angle 32.80 below the horizon across a lake as shown in the figure.   Calculate the minimum force F (in N) he must exert to get the block moving. (Hint: Horizontal component of force = Static friction force) (The coefficient of static friction is 0.1 and the coefficient of kinetic friction is 0.03)