3837
Physics Force & Laws Of Motion Level: University
Equation of MotionAn experimental rocket car starting form reaches a speed of 560 km/h after a straight 400m run on the salt flat. Assuming that acceleration is constant. What was the time of the run ? What is the magnitude of the acceleration?
3836
Physics Force & Laws Of Motion Level: University
Equation of motionThe driver of a pickup truck ( hay its oklahoma ) going 100 km/h applies the brakes giving the truck a uniform deceleration of 6.5m/s^2 while it travels 20.0m. What is the speed of the truck in kilometers per hour at the end of this distance? How much time has elapsed?
3835
Physics Current Electricity Level: University
How much current will flow through the 8.0 Ohm resistor?a. 1.0A
b. 0.29A
c. 0.50A
d. 2.0 A
e. none of the other responses is
Question Diagram
3834
Physics Current Electricity Level: University
Current & ChargeIn a certain DC circuit 1.50A of current flows through a 4.00 Ohm metal resistor for a period of 90.0S. During this time interval what is the net number of electrons that have passed through a cross- section of the resistor?
a. 135
b. 8.43 x 10^20
C. 3.37 x 10^21
d. 1.04 x 10^17
e. 5.06 x 10^21
3833
Physics Current Electricity Level: University
For the circuit shown what is the magnitude of the potential difference across the 6.00 Ohm resistor?
a. 4,50V
b. 3.60 V
c. 6.00 V
d. 6.75 V
e. 1.80 V
Question Diagram
3832
Physics Electrostatics Level: University
Electric field intensityA positive charge of 2*10^-6 coul experiences a force of 06 newton when placed at a point in an electric field. The strength of the field at that point in newton/ coul is?
3831
Physics Electrostatics Level: University
PotentialHow much work is required move an electron through a potential difference of 200 volts in an electric field?
3830
Physics Electrostatics Level: University
Coulomb's lawQ1 and Q2 represent to point charges originally a distance R ( not) apart. If the charge Q1 is tripled while charge Q2 is halved how far apart would they now have to be in order to have the same force between them as in the original situation?
3829
Physics Electrostatics Level: University
Coulomb's LawTwo protons are places 1.0 cm apart and released from rest. What is the magnitude and initial acceleration of either proton?
3828
Physics Magnetism,Magnetic Effects Of Current Level: University
Current(a) How could the direction of a magnetic field be determined by making qualitative observations of the magnetic force on a straight wire carrying current. Explain with an example
(b) Intelligent Signals
A car stops for a red light at an intersection. As it comes to a halt it moves over a coil embedded in the surface of the road. As a result the light soon changes from red to green. Explain how the coil is able to signal the light change.
(c) Automatic ON/OFF switches
A current was sent through a helical coil spring. The spring contracts as through it had been compressed and so the circuit continuity is lost. Since there is no current the helical coil stretches back and again makes contact again getting current back to the system.So the same process repeats itself working like an automatic ON/OFF (toggle) switch. Why do the spring compress when current start flowing through the circuit. Explain.
3827
Physics Magnetism,Magnetic Effects Of Current Level: University
Ampare circuital LawA conductor is made in the form of a hollow cylinder with an inner and outer radii of a and b respectively. It carries a curent I uniformly distributed over its entire cross-section. Derive expressions for the magnitude of the magnetic fielding the regions and then graph it (i) r < a (ii) a < r < d (iii) r > c
3826
Physics Rotational Mechanics Level: University
Conservation of momentumA rigid bar is suspended in the air on a frictionless pivot )at the top of the bar). The bar is uniform and has a mass M and length L.A small bullet is shot into the bottom end of the bar. The bullet has mass m and hits the rod moving horizontally with speed v. ( recall that the moment of inertia of a uniform rod about an axis perpendicular to the rod and through the center of mass is ML^2/12). Express your answer in terms of any/all of m M L g v.
1. Derive an expression for the angular velocity of the rod + bullet ( about the pivot) immediately after the collision.
2. Derive an expression for the maximum angle of deflection of the rod after the collision.
3. Derive an expression for the horizontal linear momentum impulse delivered to the rod by the pivot during the collision.
3825
Physics Rotational Mechanics Level: University
TorqueA yo-yosits initially at rest on a table top. The coefficient of static friction between the yo-yo and surface of the table is 6/10. The yo-yo consists of two disks with a rather thick central spindle around which is wrapped some string of negligible mass. the moment of inertia of the yo-yo is 2/5 m R^2 where R is the outer radius of the yo-yo and M is its mass. The radius of the spindle is R/4. Neglect the thickness of the thin massles string.
A persion pulls straight up on the string with an applied force F.
What is the largest HORIZONTAL acceleration that can be given to the yo-yo-by method. Express your answer as a multiple of g.
3824
Physics Force & Laws Of Motion Level: University
Equation of MotionSome engineering students are challenged to design a cotainer allowing them to drop an egg from a 10.0 m high dormitary roof without the egg breaking. They first wanted to dertermine that indeed without a container the egg will break if dropped. Just as they drop of the egg student carrying a load of laundry comes out of the door of the dormitary 3m away from the drop zone. The top of the pile of the laundry is 1.00m above the ground. The student is walking 1.50 m/s. A) will this student mess up the plan to see if the egg breaks? (i.e. will the egg fall in the laundry basket and not break assume basket and student are in the same place rather than the basket being held out a distance in front of the student? If not how far away will the egg land from the student? B) After that trial the students decided to try again. This time right as they drop the egg another student cames out of the same door with a load of laundry( whos top of the pile is again 1.00 above the group). This student is walking at 1.25/s. 0.5 seconds after the egg is dropped (and he exits the building) the student carrying laundry notices what has happened and decides to try to insure the egg falls in the basket 1) Does the student need to change his velocity? If so. 2) Find the acceleration?
3823
Physics Work,Power & Energy Level: University
Energy conservationAn electric motor raises two packages from the floor to a platform 3.0 meters above the floor. Both packages have the same mass. The first is pulled up a frictionless inclined plane at a constant speed of 20 cm per second . The second package is lifted vertically, at the same constant speed. Which package gets to the 3.0 meter platform first? Which required more energy? Calculate the power .
