A 20-kg girl rides on a merry-go-round. She is sitting near the edge of the merry-go-round and is rotating counterclockwise. The +z axis is defined to be perpendicular to the merry-go-round, and the +x and +y axes are in the plane of the merry-go-round. (See figures below.)
At , the velocity of the girl is m/s, and 0.15 s later, her velocity is m/s.
While playing air hockey, the puck comes toward you with a speed of 0.8 m/s at an angle of above the –x axis. You strike it with your paddle, and after the collision, the puck travels in the +x direction with a speed of 2 m/s toward the opponent's goal. The mass of the puck is 0.020 kg.
What impulse is required to accelerate a proton of mass from 0.95c to 0.99999999c (which is the maximum speed achieved with the Large Hadron Collider)? Assume that the proton travels along a straight line in the +x direction.
Earth orbits Sun in a nearly circular orbit with a speed m/s. Suppose that at a certain instant, Earth's velocity is in the –x direction. At this instant, the force by Sun on Earth is . What will be Earth's momentum 1 day later? During this time interval, the only significant force acting on Earth is the gravitational force by Sun on Earth.
An alpha particle has a speed of m/s in the +x direction when it collides with a gold nucleus. and deflects at an angle above the +x axis. Its speed after the collision nearly the same as its speed before the collision because the gold nucleus is so massive compared to the alpha particle. What is the impulse on the alpha particle due to the collision with the gold nucleus?
The thrust of a certain model rocket engine as a function of time is shown below. Here, the word "thrust" refers to the force by the exhaust on the rocket as the rocket engine is firing.
The total area under the curve is 1.84 N s. The total burn time of the rocket engine is 1.24 s. The peak thrust has a magnitude 8.60 N. Since force is a vector, assume that the thrust is in the +y direction.
In a mass spectrometer (an instrument used in chemistry to measure the mass and therefore identity of unknown atoms) positively charged ions are accelerated between two charged plates. Suppose that a proton is nearly at rest at the positively charged plate on the left. It is accelerated toward a negatively charged plate on the right, as shown below. The plates are 5 cm apart.
The electric force by the charged plates on the proton is in the +x direction. This is the only significant force acting on the proton.
You toss a nerf basketball of mass 0.002 kg into the air. At t = 0, the ball leaves your hand. At t = 0.11 s, the net force on the ball is , its velocity is , and its position is . What is its position at t = 0.13 s?