The speed of a car is increased uniformly from 20. meters per second to 30. meters per second towards the right in 4.0 seconds. The magnitude of the car's average
acceleration in this 4.0-second interval is

A 13m/s2

B 2.5m/s2

C 10m/s2

D 0.40m/s2

What is work? how much work is done to move an object 0 meters?

Because light travels in a straight line and casts a shadow, isaac newton hypothesized that light is

Africtionless piston-cylinder contains 50 l of saturated liquid r-134a. the piston has a mass and an area resulting in an applied pressure of 500 kpa on the refrigerant. the refrigerant is now heated until its temperature rises to 70∘c. calculate the work (in kj) done during this process.