PROBLEMS

1.       Is it possible that the car could have accelerated to 55mph within 268 meters if the car can only accelerate from 0 to 60 mph in 15 seconds?

2.       We drive a distance of 1 km at 16 km/h. Then we drive an additional distance of 1 km at 32 km/h. What is our average speed?

3.       An airliner reaches its takeoff speed of 163 mph in 36.2 s. What is the magnitude of its average acceleration.

4.       An airliner reaches its takeoff speed of 163 mph in 36.2 s. What is the magnitude of its average acceleration.

5.       A boy walks to the store using the following path: 0.4 miles west, 0.2 miles north, 0.3 miles east.  What is his total displacement?  That is, what is the length and direction of the vector that points from her house directly to the store?

6.       (a) If a particle's position is given by   (where t is in seconds, and x is in meters), what is it's velocity at t=1s? 

(b) what is it's speed at t=1s? 

(c) Is there ever an instant when the velocity is 0?  If so, give the time.

7.       If an object weighs 30 N on Earth, how much would it weigh on the moon

8.       A boy of mass 40 kg wishes to play on pivoted seesaw with his dog of mass 15 kg. When the dog sits at 3 m from the pivot, where must the boy sit if the 6.5 me long board is to be balanced horizontally?

9.       The value of g at the surface of the earth is 9.78 N/kg, and on the surface of Venus the magnitude of g is 8.6 N/kg. A cosmonaut has a mass of 60 kg on the surface of the earth. What will her weight be on the surface of Venus?

10.  If a 5 tons beam is raised 6 meters, what is it's potential energy? If it is raised another 8 meters in 6 seconds, what is the work done?

11.  A cat stuck up a tree and has 500 J gravitational potential energy. It then falls. Find the kinetic energy of the cat just before it is caught by the owner. Find the kinetic energy of the cat after it is caught by the owner. Find the wasted energy (after cat is caught by the owner).

12.  A constant force of 80 N acts for 8 s on a box of mass 10 kg horizontally that initially rests on a horizontal frictionless surface.

(a) Find the change in the box's momentum.

(b) Calculate the final speed of the box after the 8 s have passed.

13.  Problem 1. How much work has been done by an ideal gas, when the temperature of 5 moles of the gas increases by 2 Kelvin in an isobaric process?

14.  If ice has a density of 0.92 kg/m³, then what is the volume of 5,000 g of ice?

15.  What is an atomic mass of NaOH ?

16.  An ice cube having a mass of 50 grams and an initial temperature of -10 degrees Celsius is placed in 400 grams of 40 degrees Celsius water. What is the final temperature of the mixture if the effects of the container can be neglected?

17.  Two small spheres spaced 35.0cm apart   have equal charge.  How many excess electrons must be present on each sphere if the  magnitude of the force of repulsion between them is ?

18.  A point charge is at the point , , and a second point charge is at the point , .  Find the magnitude and direction of the net electric field at the origin.

19.  What must the charge (sign and magnitude) of a particle of mass 5 g be for it to remain stationary when placed in a downward-directed electric field of magnitude 800 N/C?

20.  Two particles having charges of 0.70 nC and 12 nC are separated by a distance of 2 m. At what point along the line connecting the two charges is the net electric field due to the two charges equal to zero?  

21.  Each of the protons in a particle beam has a kinetic energy of . What are the magnitude and direction of the electric field that will stop these protons in a distance of 2 m?

22.  How many excess electrons must be added to an isolated spherical conductor 27 cm in diameter to produce an electric field of 1450 N/C just outside the surface?

23.  A parallel-plate air capacitor has a capacitance of 800 pF. The charge on each plate is 6 µC. What is the potential difference between the plates?

24.  You want to create an electric field at location . Where would you place a proton to produce this filed at the origin? Instead of a proton, where would you place an electron to produce this filed at the origin?

25.  A parallel-plate air capacitor of capacitance of 100 pF has a charge of magnitude 0.1 µC on each plate. The plates are 0.5 mm apart.

(a) What is the potential difference between the plates?

(b) What is the area of each plate?

(c) What is the electric-field magnitude between the plates?

(d) What is the surface charge density on each plate?