A person lifts an object of mass m from the bottom of a well at a constant speed of v for a time t. How much power P is exerted by the person on the object?

A 3 kg box sits on a spring (k = 100 N/m), which is secured to the floor of a rocket deep in space (far from any gravitational force). The rocket is accelerating forward with an acceleration of 2 m/s2. What is the compression (

An object of mass 1 kg that is moving along the x axis experiences a net force as indicated in the graph. When located at x = 0, the object has a kinetic energy of 1000 J and is moving in the +x direction. What is the kinetic energy of the object when it reaches x = 10 m?

A 2 kg mass attached to a massless spring undergoes undamped simple harmonic motion, with a position given by

A 2 kg mass is oscillating on a spring subject to a linear damping force with coefficient b = 2 kg/s. The initial energy in the system is about 10 J.  After 10 seconds the spring potential energy of the system is approximately : Note that

In a classic amusement park ride, riders stand against the wall in a cylindrically shaped room. Once the room gets spinning fast enough, the floor drops from the bottom of the room, and the riders remain stuck to the wall.  At the instant shown in the figure, where the rider is on the left, the free body diagram of the rider of mass m is given by: v denotes the tangential speed of the rider

Answer the questions according to your situation.  (Type Chinese characters and complete sentences)   1. 你几岁？nǐ jǐ suì ? 2. 今天几月几号？ jīn tiān jǐ yuè jǐ hào ? 3. 现在几点？xiàn zài jǐ diǎn ? 4. 明天星期几？ míng tiān xīng qī jǐ ?  

Exaptation involves the adaptive repurposing of a preexisting morphological character to serve a new function.

Acritarchs are microfossils of green microalgae thereby providing fossil evidence that eukaryotes originated by a least 2.0 Ga.

The oldest definitive body fossils of metazoan animals are from the: