Physics
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An electron with a speed of 3.0 × 106 m/s collides with an atom which has the following energy levels: n1 = -24.6 eV, n2 = -5.4 eV, and n3 = -2.4 eV. The atom emits a 619.9 nm photon after the collision. Ignoring the atomic recoil, since the atom's mass is significantly larger than the electron's mass, determine what the electron's final speed will be. Note that the photon energy ≠ collision energy.
During a football match, a player attempts to score a goal, but he misses and the ball with a speed of 55 m/s hits the goalpost and rebounds back with the same speed. The force exerted by the goalpost on the ball is depicted in the graph below. Determine the maximum force exerted by the goalpost on the ball if the mass of the football is 425 g. Consider the motion towards the right as positive.
Determine the combined speed immediately after a collision where a 131-kg robot, moving at 2.6 m/s, collides head-on with (and holds on to) an 83-kg drone moving at 5.1 m/s towards the robot.
A solar panel generates an average power output of 150 watts from sunlight hitting its surface perpendicularly during peak hours; calculate the reaction force experienced by the solar panel due to emitted infrared radiation, assuming all generated energy is radiated away as infrared and is perpendicular to the surface.
A truck with a mass of 9000 kg is moving at a constant velocity of 20 m/s. A sandbag weighing 1000 kg initially stationary falls vertically and lands in the back of the truck. What is the new velocity of the truck after catching the sandbag?
A firefighter is standing on a 40.0-kg flatbed cart that is initially at rest on a frictionless surface. The firefighter has a mass of 60.0 kg. He throws a 7.0-kg fire extinguisher horizontally with a speed of 8.0 m/s to a fellow firefighter standing nearby. Calculate the velocity of the cart immediately after the extinguisher is thrown, assuming it was initially at rest.