Three forces acting on an object are given by F1 = (−2.00 i + 2.00 j) N, F2 = (5.00 i − 3.00 j) N, and F3 = (−45.0 i) N. The object experiences an acceleration of magnitude 3.75 m/s2. i. What is the direction of the acceleration?

ii. What is the mass of the object?

iii. If the object is initially at rest, what is its speed after 10.0 s?

iv. What are the velocity components of the object after 10.0 s?

When the displacement of a mass on a spring is 12a the half of the amplitude, what fraction of the mechanical energy is kinetic energy? at what displacement, as a fraction of a, is the mechanical energy half kinetic and half potential?

You are driving to the grocery store at 20 m/s. you are 110m from an intersection when the traffic light turns red. assume that your reaction time is 0.50s and that your car brakes with constant acceleration. how far are you from the intersection when you begin to apply the brakes? what acceleration will bring you to rest right at the intersection? how long does it take you to stop after the light changes? the known values: vi=20m/s xi=110m t=.50s vf=0m/s xf=0m a=?

Suppose two stars are located in region a of the h-r diagram shown in the figure below. star c appears much dimmer than star y as seen from earth. which star can be inferred to be nearer to earth and how do you know?