Mechanics | Relativity Answers

A young boy swings a yo-yo horizontally above his head so that the yo-yo has a centripetal acceleration of 240 m/s[sup]2[/sup]. If the yo-yo’s string is 0.56 m long, what is the yo-yo’s tangential speed?

An 80 kg astronaut is floating at rest a distance of 10 m from spaceship when he runs out of oxygen to power him back to the spaceship.He removes his oxygen tank(3 kg) and push it into space away from the ship with a speed of 15 meter per second.

a.At what speed does he recoil toward the spaceship?
b.How long must he hold his breath before reaching the ship?

You throw a 0.345kg ball straigt up with an initial velocity of 13.5m/s

a. what is the momentum of the ball at the highest point of its path?
b. what is its momentum halfway up?
c. what is its kinetic energy halfway up?

It takes you all of 0.018s to initially touch and then catch a 0.600kg football travelling at 16.0m/s

a. what is the change in momentum for the football?
b. what is the impulse?
c. what is the force that must be exerted to stop the ball?

If two objects have an inelastic collision and one is intitally at rest, is it possible for both of them to be at rest after the smash up? Is it possible for only one of them to be at rest? Why?

A car and its driver travelling at a velocity of 18 meters per second are stopped abruptly by a collision with the rear end of a packed van.The cars front end is pushed by 0.55 meters by rhe collision.The 60 kg driver who was restrained by the seat belt and shoulder strap is also stopped at 0.55 meters.Calculate

a. The time the car has stopped.
b. The average force acting on the driver.
c. The deceleration of the drive.

Application of reflection and refraction in visible light spectroscopy.

A 11.7 kg mass attached to a spring scale rests on a smooth, horizontal surface. The spring scale, attached to the front end of a boxcar, reads T = 40.1 N when the car is in motion. If the spring scale reads zero when the car is at rest, determine the acceleration of the car, when it is in motion as indicated above.

Assume the driver has a mass of 72.4 kg . What horizontal force does the seat exert on the driver?

A dragster and driver together have mass
888.7 kg . The dragster, starting from rest,
attains a speed of 25.4 m/s in 0.55 s .
Find the average acceleration of the drag-
ster during this time interval.
Answer in units of m/s2