As part of a class demonstration, a physics teacher sits down on a rolling office chair while holding a fire extinguisher. The total mass of the teacher+chair+extinguisher is M = 82.0 kg. Starting from rest, she aims the fire extinguisher horizontally and squeezes the handle. Over the course of a few seconds, ∆m = 4.00 kg of carbon dioxide is ejected from the extinguisher with a speed of v = 20.0 m/s relative to the ground. a) What is the total kinetic energy KE contained in the system (teacher+chair+extinguisher+ejected carbon dioxide) at the end of the demonstration? (You may neglect any friction in the wheels of the chair.) b) As (∆m → 0), what does KE approach?

on the glassy ice, a 70 kg skater sits. He propels himself forward by shooting a 3 kg ball horizontally at a pace of 8 m/s. After shooting the puck, how fast can the skater move? The coefficient of friction between the ice and the skated is f = 0.02.

A 9 kg steel ball strikes a wall with a speed of 4.98 m/s at an angle of 30.7° with the normal to the wall. It bounces off with the same speed and angle, as shown in the figure. y 4.98 m/s 30.7° T 30.7° 9 kg 9 kg 4.98 m/s x If the ball is in contact with the wall for 0.255 s, what is the magnitude of the average force exerted on the ball by the wall? Answer in units of N. Your response... i Previous Responses X #1. 201.5089 PALETTE

A 7.00 g bullet, when fired from a gun into a 1.00 kg block of wood held in a vise, penetrates the block to a depth of 6.40 cm. This block of wood is next placed on a frictionless horizontal surface, and a second 7.00 g bullet is fired from the gun into the block. To what depth will the bullet penetrate the block in this case? × Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully. cm

A 4.10-kg steel ball strikes a wall with a speed of 13.0 m/s at an angle of ? = 60.0° with the surface. It bounces off with the same speed and angle (see figure below). If the ball is in contact with the wall for 0.200 s, what is the average force exerted by the wall on the ball?

You wake up one morning to find yourself in a strange room with opaque walls, and no visible doors or windows. You decide to do some experiments to find out more about your strange situation. Your own body mass is 72.4 kg. You pick up an object and drop it from rest, starting at a height of 1.72 meters above the floor, and it hits the floor 0.415 seconds later. You can ignore air resistance. Based on the outcome of this experiment, when you step on the scale provided for you, what weight will it register for your body?     710.2 N     723 N     964 N     1,446 N

Please answer and solve the question correctly. Thank you!

Three carts are moving on a frictionless horizontal track as shown in the figure.  The 4.00 kg cart is moving to the right with a speed of 7.0 m/s, the 10.0 kg cart is also moving to the right with a speed of 6.0 m/s while the 3.00 kg cart moves to the left with a speed of 7 m/s.  Find the final speed of the carts when they are all stuck together.   Hint:  The order at which the carts stick together does not matter.  Can you see why?

A 156 g cart moves on a horizontal, frictionlesssurface with a constant speed of 11.1 cm/s.A 60.6 g piece of modeling clay is droppedvertically onto the cart.If the clay sticks to the cart, find the finalspeed of the system.Answer in units of cm/

An unfortunate astronaut loses his grip during a spacewalk and finds himself floating away from the space station, carrying only a rope and a bag of tools. First he tries to throw a rope to his fellow astronaut, but the rope is too short. In a last ditch effort, the astronaut throws his bag of tools in the direction of his motion, away from the space station. The astronaut has a mass of ma = 102 kg and the bag of tools has a mass of mp = 19.0 kg. If the astronaut is moving away from the space station at Vj = 2.10 m/s initially, what is the minimum final speed vp.f of the bag of tools with respect to the space station that will keep the astronaut from drifting away forever? Ub.f = m/s