1. A car is initially moving at 50 km/h along a straight highway. To pass another car, it speeds up to 140 km/h in 20 seconds at a constant acceleration.
(a) How large was the acceleration in m/s 2
(b) How large was the acceleration, in units of g = 10 m/s 2 ?
2. Convert the following quantities into Standard Units of Physics (SI), showing all the conversion factors with units referring to Lecture 1 and 2.
- x = 14 feet
- A =2.00mi^2
3. A 2000-kg car initially has a velocity of 25 m/s due south. It brakes to a stop over a 200- m distance.
(a) What is the magnitude of the car's acceleration, in m/s 2
(b) What average net force magnitude was necessary to stop the car?
(c) Assuming the tires do not skid, what coefficient of static friction between tires and pavement is needed?
4. A 50-kg particle has a speed of 2.0 m/s at point A and a KE of 50 J at point B, what is, (a) it's kinetic energy at A? (b) Its speed at point B? (c) The total work done on the particle as it moves from A to B?
5. A 50-kg particle has a speed of 2.0 m/s at point A and a KE of 50 J at point B, what is, (a) it's kinetic energy at A? (b) Its speed at point B? (c) The total work done on the particle as it moves from A to B?