A Red Rider bb gun uses the energy in a compressed spring to provide the kinetic energy for propelling a small pellet of mass 0.22 grams. By cocking the lever attached to the stock of the rifle, the spring (k = 1800 N/m) is compressed 9 cm from its equilibrium point. What is the potential energy energy stored in the compressed spring? Submit Answer Tries 0/2 What is the kinetic energy of the pellet when the spring is released? Submit Answer Tries 0/2 What is the muzzle velocity of the bb? m/s

You push a box up a ramp (friction between the box and the ramp is not negligible). Call the initial state when you begin to push the box. Call the final state after you have pushed the box up the ramp a distance of 0.5 m and it is moving with a speed of 2 m/s For which of the following systems does the energy remain constant?A. System: box + ramp + Earth + youB. System: boxC. System: box + ramp + EarthD. System: youE. System: box + rampF. None of the above.   Two cars are driving down the road. They notice that they are going to crash, so both drivers slam on the brakes. The cars skid, but still collide. The cars stick together and eventually slide to a stop. Call the initial state just before the drivers apply the brakes and the final state just after the collision had occurred. Treat this situation as realistically as possible. For which of the following systems does the energy remain constant?A. System: both carsB. System: both cars + the groundC. System: the second carD. System:…

A spring has a natural length of 2 ft.  A force of 20 lb stretches the spring to a length of 3 ft.  Find the spring constant.  Then calculate the amount of work done in stretching the spring from its natural length to 3 ft.  How much work is done in stretching the spring from 4 ft to 5 ft.  How far beyond the natural length will a 30 lb force stretch the spring?

1. A roller-coaster car with a mass of 1200 kg starts at rest from a point 20 m above the ground. At point B, it is 9 m above the ground. [Express your answers in kilojoules (kJ).] a. What is the initial potential energy of the car? b. What is the potential energy at point B? c. If the initial kinetic energy was zero and the work done against friction between the starting point and point B is 40 000 J (40 kJ), what is the kinetic energy of the car at point B 2. The time required for one complete cycle of a mass oscillating at the end of a spring is 0.80 s. What is the frequency of oscillation?

The potential energy of an interaction is given by U(x)=ax², where a = +6.4 J/m². Initial speed of a 0.79-kg object in this system is 2.63 m/s at x = 0. A. How far does the object travel before it reaches a speed of v = 0? Express your answer with the appropriate units. B. Does your answer in the previous part depend on whether the object is traveling in the positive or negative  direction? Yes, the answer in the previous part is for the object traveling in the negative x� direction, the distance for the object traveling in the positive x� direction is greater than the obtained result. Yes, the answer in the previous part is for the object traveling in the positive x� direction, the distance for the object traveling in the negative x� direction is greater than the obtained result. No, it does not depend on whether the object is traveling in the positive or negative x� direction.

A mouse is on a crazy roller coaster which has five distinct phases.  The mouse in his roller coaster car has a mass of 6 kg. The mouse starts the coaster by being pulled back 0.2 m into a spring with a spring constant of 1890 N/m. How much elastic potential energy does the mouse have as he starts his ride? After the spring is released, the mouse travels over the first hill, effectively coming to rest at the top. Calculate the height of the first hill? He then speeds into a valley. At the bottom of the valley 3 J of energy is lost due to friction. What is his total remaining energy after he travels through the valley? The mouse then travels over a 0.10 m hill. How fast is the mouse traveling over the hill at point D?  The mouse finally makes it to the final phase of the ride, where he will race along at ground level. How fast is he traveling at point E?

Q 3. Three cars are traveling at 30km/h, 50km/h and 200km/h, respectively. Each speed corresponds to a certain kinetic energy. a)  Note down the expression for the kinetic energy of a moving object with a velocity v. b)  Note down the potential energy for an object lifted up from the ground to height h. c)  Based on a) and b) find an expression for the height as a function of velocity by assuming that the kinetic energy equals the potential energy of the same object. In other words find h(v) from which the object would need to be dropped and calculate the height so it has a speed of 30 km/h, 50 km/h or 200 km/h on impact with the ground. Assume free fall without air resistance d)  Comment on your chances of survival if you are involved in head-on collisions for the three different speeds.