Description
1. A 0.5 kg ball on the end of a horizontal cord revolves in a circle of radius 1.1m on a frictionless horizontal surface. If the ball can rotate at a maximum speed of 17 m/s before the cord breaks, what was the maximum tension in the cord before the break?
2. What is the acceleration due to gravity at the surface of a planet of mass 4 x 1023 kg, and radius 2500 km.?
3. When you stand on a bathroom scale in an elevator your mass reads as 79 kg. If the elevator is accelerating upwards at 2.5m/s^2. What is you actual mass
4. Estimate the work you do to mow a lawn 28m by 18m with a 40cm wide mower.
Assume you push with a force of 22N.
5. At an accident scene on a level road, investigators measure a car’s skid mark to be 65m long.
It was a rainy day and the coefficient of kinetic friction was estimated to be 0.25.
Use these data to determine the speed of the car when the driver slammed on (and locked) the brakes.
6.A 1200-kg car moving on a horizontal surface has speed v = 80 km/hr
when it strikes a horizontal coiled spring and is brought to rest in a distance of 4.5m.
What is the spring stiffness constant of the spring?
7. Use this information to answer the following two questions:
A 90 kg astronaut (including space suit) acquires a speed of 2.9 m/s
by pushing off with her legs from a 2500 kg space capsule.
(a) What is the speed of the space capsule?
(b) If the push lasts 0.5s, what is the average force exerted by each on the other?
8. A 0.35-kg croquet ball makes an elastic head-on collision with a second ball initially at rest.
The second ball moves off with half the original speed of the first ball.
What is the mass of the second ball?
