Physics 105| Final Exam

A person travels south at a constant speed of 3 m/s in a straight line from town A to town B. Then he goes back at a constant speed of 7m/s from town B to town A in a straight line. Find the average speed in m/s during the entire trip.

A 3.0 kg box slides down a 20.0-degree incline with an initial speed of 4.5 m/s. The coefficient of kinetic friction between the box and the incline is 0.55. What is the acceleration of the block ( in m/s^2 )?

If Two objects M1, M2 (M1=M2 ) are connected by a light inextensible cord which is attached to the ceiling of an elevator that is accelerating upward at 2 m/s^2, the ration T/N is:

With a 307 J of kinetic energy, a 2 kg ball starts sliding up a rough ramp with an inclination of 30°. How far (in m) will the ball slide up the ramp knowing that the coefficient of kinetic friction between it and the ramp is 0.4?

A traffic light hangs from a pole as shown in the figure. The uniform aluminum pole AB is 7.2 m long and has a mass of 6.0 kg. The mass of the traffic light is 21.5 kg. Find the tension in the horizontal massless cable CD?

A rectangular block of mass m is placed in a fluid and acted upon by a force F such that the block is fully submerged and hangs in static equilibrium. If the density of the block is twice that of the fluid, the magnitude of the force F is:

Consider that your average blood pressure is (1.33 N/cm^2 ) and your blood flow rate is (105 cm^3/s ). The energy your heart does provide in one day is used to lift a 72 kg box vertically to a height of h. Calculate the height h (in m).

At t=0, the activity of sample Q is 8 mCi and that of sample W is 2 mCi. After 13 weeks, the two samples have the same activity of 0.25 mCi. The ratio of the mean lifetime of W to the mean lifetime of Q is? (Recall that 1 Ci=(3.7*10^10 Bq ).

The radioactive Iodine -131, which has a half-life of 8.02 days, is used for the diagnosis of the Thyroid gland. A patient was administered 10 micrograms of radioactive Iodine -131. After 3 days, the amount (in micrograms) remaining in his body is approximate: (Recall that ( 1 Ci=3.7*10^10 Bq, NA=6.02*10^23 ).

Two radioactive samples A and B with half-lives TA and TB=2TA. Assuming the initial numbers of both samples are equal, which of the following statements is correct?