Question 1: An object, which is initially at rest on a frictionless horizontal surface, is acted upon by four constant forces. F1 is 28.6 N acting due East, F2 is 32.8 N acting due North, F3 is 39.2 N acting due west, and F4 is 20.7 N acting due south.
a) How much total work is done on the object in 3.33 seconds, if it has a mass of 14.0 kg?
b) Which type of energy is changing for the object while the above work is being done?
c) How fast does the object end up moving at the end of the 3.33 seconds?
Question 2: A 20.0-g object is placed against the free end of a spring (with spring constant k equal to 25.0 N/m) that is compressed 10.0 cm. Once released the object slides 1.25 m across the tabletop and eventually lands 0.96 m from the edge of the table on the floor, as shown in the figure. Calculate the coefficient of friction between the table and the object. The sliding distance includes the compression of the spring and the tabletop is 1.00 m above the floor level.
![2269_2.png](https://secure.tutorsglobe.com/CMSImages/2269_2.png)
Question 3: A block of mass m = 3.65 kg slides along a horizontal table with speed vo = 7.00 m/s. At x = 0 it hits a spring with spring constant k = 43.00 N/m and it also begins to experience a friction force. The coefficient of friction is given by p = 0.250. How far has the spring compressed by the time the block first momentarily comes to rest?
![1428_3.png](https://secure.tutorsglobe.com/CMSImages/1428_3.png)
Question 4: A single 218Th nucleus, initially at rest, emits an alpha particle as it decays into a 214Ra nucleus. There are no other decay products, and the kinetic energy of the alpha particle is measured to be 1.549 x 10-12 J.
a) What is the total amount of nuclear potential energy, in joules, that was released in this process?
b) What is the difference between the original mass of the 218Th nucleus and the total mass of the fragments (214Ra and alpha particle) after the decay?