Friday

August 28, 2015
**Physics**

An electric lawn mower has a resistance of 160 ohms and draws 15A. What is the cost of operating the lawn mower for 30 minutes if electrical energy costs $0.12/kWh?
*Monday, June 16, 2014 by M*

**Physics**

A 66.2 kg person sits on the 5.3 kg sled (slope is on an angle, angle not given). It is to be pulled across the snow with a coefficient of friction equal to 0.12. What horizontal force is required to pill the sled at a constant speed?
*Monday, June 16, 2014 by M*

**physics**

a copper wire has a diameter of o.5mm and resistivity of 1.6*10power 6 ohm cm.calculate the length of wire which will be necessary to make 10 ohm coil
*Monday, June 16, 2014 by kanika*

**physics**

if an object has covered first 30 m distance in 5 sec and other 40 m distance in 20 min.find the average speed in cgs system.
*Monday, June 16, 2014 by srishti*

**physics please help!!!!!!**

a mass is thrown vertically upwards with an initial velocity of 30m/s. a second mass is dropped 0.5s later from directly above a height of 60m from the first mass. when do they meet and at what height?
*Monday, June 16, 2014 by adii *

**physics**

a man moves 2km/hour and rain has started now falling with 2km/hour at what angle should umbrellla be kept so that man can not go wet
*Monday, June 16, 2014 by aadil*

**Physics**

Josh starts his sled at the top of a 3.0m high hill that has a constant slope of 25 degrees. After reaching the bottom, he slides across a horizontal patch of snow. The hill is frictionless but the coefficient of kinetic friction between his sled and the snow is .05. How far ...
*Monday, June 16, 2014 by Tiffany*

**Physics **

The diagram shows a weightlifter in the initial stages of his lift. He lifts two 70 kg masses connected to a 10 kg bar. In addition, there are two upward forces : 795N and 810N a. Calculate the total weight that he is lifting? b. Calculate the size of the acceleration of the ...
*Sunday, June 15, 2014 by Sandra*

**physics**

If h is 5m and the mass takes 3 s to move the distance d when starting from rest, what is the distance d? PLEASEEEEEE!!!!
*Sunday, June 15, 2014 by yan*

**Physics**

To qualify for the finals in a racing event, a race car must achieve an average speed of 225 km/h on a track with a total length of 1.4 km. If a particular car covers the first half of the track at an average speed of 205 km/h, what minimum average speed must it have in the ...
*Sunday, June 15, 2014 by Piper*

**Physics**

In 1926, Johnny Weissmuller set the men’s world 400.0-m swimming record in 4.00 min, 57.0 s. In 1966, Martha Randall set the women’s record in 4.00 min, 38.0 s. By how many meters would Martha have been beaten Johnny if they had raced each other?
*Sunday, June 15, 2014 by Piper*

**physics**

a strong 100 kg man pushes down hard on the left piston. What happenes to the 10 kg mass on the right? The answer is the moves down, lifting the left piston despite the strong man. BUT WHY?
*Sunday, June 15, 2014 by nic*

**physics**

A submarine dives down to a depth 9.5 beneath the surface of the ocean. Calculate the pressure in atmospheres at that depth, assuming the density of water is 1029 kg/m3, and the air pressure at the surface is 101.5 kPa
*Sunday, June 15, 2014 by jake*

**physics**

A mass of 2.9 g is hanging underneath a spring which has an unknown spring constant. The period of oscillation is 5.5 seconds. Find the spring constant in N/m. Give your answer to 2 s.f.
*Sunday, June 15, 2014 by jake*

**physics**

A spring and mass system are oscillating with an amplitude of 8.4 cm. The spring constant is 204 N/m and the mass is 540 g. Find the mechanical energy of the system to 2 sf.
*Sunday, June 15, 2014 by jake*

**physics**

Which one of the following statements about an object performing Simple Harmonic Motion is TRUE? Select one: a. The object reaches its maximum speed as it passes through the equilibrium point. b. The object’s velocity is never zero. c. The object has a constant velocity. ...
*Sunday, June 15, 2014 by jake*

**physics**

as Sue runs, her knee joint passes through the following vertical positions (meters): Frame 1: .043 Frame 2: .145 Frame 3: .21 Frame 4: .39 Frame 5: .415 The data were collected at a frequency of 100 Hz. What was the vertical velocity of her knee joint at the 2nd time point?
*Sunday, June 15, 2014 by chris*

**physics**

a skater is sliding forward on a flat rink at 6 m/s. her mass is 71 kg. the sliding friction acting on her skate blade is 13.4 N acting backward. air resistance is 14.7 N acting backward. what is her horizontal acceleration?
*Sunday, June 15, 2014 by Rob*

**physics**

a string supports a solid iron object of mass 180g totally immersed in liquid of density 800kg/m3. calculate the tension in the string if the density of iron is 8000kg/m3.
*Sunday, June 15, 2014 by joelinho*

**physics**

a box of treasure with a mass of 92 kg and volume of 0.031metrecubic lies at the bottom of the ocean.how much force is needed to lift it?
*Sunday, June 15, 2014 by joelinho*

**physics**

If two stones projected from the same point with the same speed but at angles pi/3 and pi/6 respectively have their ranges R₁ and R₂ then a)R1=2R2 B)R1=R2 C)R1=5R2 D)R1=25R2
*Sunday, June 15, 2014 by fatima*

**physics**

a pendelum in a fathers clock measures .90m from the support to the centerof the bob
*Sunday, June 15, 2014 by Anonymous*

**Physics**

Assuming the best high jump record from a standingposition in a school was 1.52 m, what initial velocity was needed for this jump? Neglect any sideways motion.
*Sunday, June 15, 2014 by Han*

**Physics**

A 0.2kg ball is attached to a rope and is whirled in a horizontal circle. Calculate the maximum speed of the ball if the length of the rope is 0.8m and its breaking strength is 0.9N
*Saturday, June 14, 2014 by alice*

**Physics**

A wheel with radius of 25cm turning at 120 rpm uniformly increases its frequency to 660 rpm in 9s. Determine: i) the centripetal acceleration ii)the total acceleration of the system
*Saturday, June 14, 2014 by alice*

**Physics**

The rocket sled shown in Figure 4.5 accelerates at a rate of 29.0 m/s2. Its passenger has a mass of 66.0 kg. Calculate the direction and magnitude of the total force the seat exerts against his body.
*Saturday, June 14, 2014 by Michelle*

**Physics**

Two teams of nine members each engage in a tug of war. The first team's members have average masses of 67 kg and exert average forces of 1350 N horizontally. The second team's members have average masses of 72 kg and exert average forces of 1361 N horizontally. (a) ...
*Saturday, June 14, 2014 by Michelle*

**Physics**

A 45-t electric train accelerates uniformly from a station with the train’s motion depicted in the graph in Figure 2.(Recall that 1 t = 1.0 × 103 kg.)Determine the net force acting on the train during the uniform acceleration portion of the motion.
*Saturday, June 14, 2014 by Han*

**physics**

The cg of the 50.0 N pole held by the pole vaulter is 2.00 m from the left hand, and the hands are 0.700 m apart. Calculate the force exerted by each hand.
*Saturday, June 14, 2014 by Anonymous*

**physics**

You have an spring gun. The end of the gun is at 1 meter above the ground. This gun is shoot horizontally with no air resistance. The cannon ball hits the ground 1.32 meters ahead from it was shoot. What is the cannon ball's initial velocity?
*Saturday, June 14, 2014 by Ash*

**Physics**

A person is carrying a plank of wood 2.00 m long with one hand pushing down on it at one end with a force F1 and the other hand holding it up at 50.0 cm from the same end of the plank with force F2. If the plank has a mass of 20.0 kg and its center of gravity is at the middle ...
*Saturday, June 14, 2014 by Anonymous*

**Physics**

The Yukon Quest, an annual dog-sled race between Whitehorse in the Yukon and Fairbanks in Alaska, covers a gruelling distance of 1.61 × 103 km. Assuming that the average speed of the dog team that set a course record is 6.28 km/h, determine the best time for this race. ...
*Saturday, June 14, 2014 by Han*

**Physics**

An unknown mass has an acceleration of 2 m/s2 to a 1 kg body.if the same force accelerate another body of 8 m/s2 .what is the mass of the body?
*Saturday, June 14, 2014 by Espie*

**Physics**

A 10 kg is acted upon by a force of 90 N .What acceleration is imparted?
*Saturday, June 14, 2014 by Espie*

**PHYSICS**

racing car accelerates uniformly. changes with following average speeds 20m/s for 2sec ;40m/sec for 2s and 60m/s for 6sec . what is overall average speed of car
*Saturday, June 14, 2014 by AYESHA*

**Physics**

A 0.020 rubber stopper is swung in a horizontal circle by 0.80 cm thread that makes 30.0 revolution every 20 seconds. a.) what is the stopper's speed? T=? v=(2pi(r))/T
*Saturday, June 14, 2014 by Roy*

**Physics**

An object is 30.0 cm to the left of a convex lens with a focal length of +8.0 cm. Calculate the distance from the lens. Would it be upright or inverted?
*Friday, June 13, 2014 by Me and I*

**PHYSICS**

IF EARTH WERE TO ROTATE FASTER THAN ITS PRESENT SPEED THEN WEIGHT PF OBJECT WILL DECREASE AT EQUATOR BUT REMAIN UNCHANGED AT POLES why?
*Friday, June 13, 2014 by AYESHA*

**PHYSICS**

if force acts on body WHOSE ACTION LINE does not Passes through its center of gravity then body will experience A ANGULAR ACCELERATION b linear acceleration C ZERO ACCELERATION D ZERO ACCELERATION
*Friday, June 13, 2014 by AYESHA*

**Physics**

Okay last question I need help with Monochromatic light of 605 nm falls on a single slit, which is located 85 cm from a screen. The first dark band appears at 5.4 mm from the center. How wide is the slit? 0.001 mm 0.050 mm 0.095 mm 1.50 mm
*Friday, June 13, 2014 by Me and I*

**Physics**

A singer moves a note up one octave. How has the sound changed? The amplitude has decreased The wavelength has increased The speed has increased The frequency has increased <-- im not sure, but i'm thinking that it's this one
*Friday, June 13, 2014 by Me and I*

**Physics**

A forklift exerts an upward force of 2.00*10^3 N on a box as it moves the box 5.00 m higher. How much work does the forklift do? 500 J 1.00*10^3 J 1.00*10^4 J <--- 0.00 J
*Friday, June 13, 2014 by Me and I*

**Physics**

How would i solve this? A 10.0 kg ball falling at 10.0 m/s hits a pile of feathers and comes to a complete stop in 10 s. What force does the pile of feathers exert to stop the ball? 10 N 20 N 100 N 200 N
*Friday, June 13, 2014 by Me and I*

**physics**

A person standing on top of a building throws a ball with a horizontal velocity of 14 m/s. If the ball strikes the ground 65 m from the base of the building, how high is the building?
*Friday, June 13, 2014 by Dasa *

**Physics**

an ice block at 0 degree celcius is dropped from height 'h' above the ground. what should be the value of 'h' so that it just melts completely by the time it reaches the bottom assuming the loss of whole gravitational potential energy is used as heat by the ice...
*Friday, June 13, 2014 by Yogesh*

**PHYSICS**

ANGULAR VELOCITY OF SECOND HAND OF WATCH IS a 2pi /30sec B pi/30sec C pi/60sec D PI/1800
*Friday, June 13, 2014 by AYESHA*

**PHYSICS**

monkey is accelerating down string whose breaking strength is two third of its weight the min acceleration of monkey should be A 1/3g B 2/3g C G d ZERO
*Friday, June 13, 2014 by AYESHA*

**physics**

on a trip a car covers 42.3 miles in 40.0 minutes. find the average velocity in m/s and km/hr
*Friday, June 13, 2014 by roger*

**physics**

A car of mass 537 kg is moving 32.0° North of East at a speed of 22.7 m/s. What is the magnitude of the momentum of the car? (magnitude - how big is it? ignore direction)
*Friday, June 13, 2014 by Anonymous*

**Physics**

Identical point charges of +1.1 ¦ÌC are fixed to three of the four corners of a square. What is the magnitude q of the negative point charge that must be fixed to the fourth corner, so that the charge at the diagonally opposite corner experiences a net force of ...
*Friday, June 13, 2014 by Bin*

**Physics**

A proton and an electron are moving due east in a constant electric field that also points due east. The electric field has a magnitude of 8.0 ¡Á 104 N/C. Determine the magnitude of the acceleration of the proton and the electron.
*Friday, June 13, 2014 by Bin*

**physics**

The weightless strut in the figure below is not attached to the wall; it is prevented from falling only by friction. (Let w = 360 N, L = 5.25 m and h = 3.25 m.) (a) Find the magnitude of the force of friction between the wall and the strut. (b) Find the normal force exerted by...
*Thursday, June 12, 2014 by Anonymous*

**physics**

If the coaster is going to make it to point C it needs to start with some initial velocity. If point C is 21 meters high and the coaster starts at a height of 20 meters, what would its initial velocity need to be if no energy is lost to friction?
*Thursday, June 12, 2014 by Davon *

**physics**

(a) Find the force P that must be applied to a piston of area 10.60 cm2 to produce sufficient fluid pressure to support a car weighing 12,101 N by means of a column of fluid of cross sectional area 285 cm2 as seen in the figure below. F1/A1=F2/A2 F1=F2*A1/A2 12101*10.6/285 =...
*Thursday, June 12, 2014 by Anonymous*

**Physics**

An object with mass 3.0 kg is executing simple harmonic motion, attached to a spring with spring constant k =210 N/m. When the object is 0.23 m from its equilibrium position, it is moving with a speed of 0.72 m/s. (a) Calculate the amplitude of the motion. m (b) Calculate the ...
*Thursday, June 12, 2014 by Garrett*

**Physics**

A 7.50 kg bowling ball strikes a stationary 4.50 kg bowling ball. After the collision, the 4.50 kg ball is traveling 8.50 m/s 30.0° east of north; the 7.50 kg ball is traveling 6.50 m/s 20.0° south of east. What was the initial velocity (magnitude and direction) of the...
*Thursday, June 12, 2014 by Anonymous*

**physics**

A mass m is gently placed on the end of a freely hanging spring. The mass then falls 21.3 cm before it stops and begins to rise. What is the frequency of the oscillation? I found the same question (with a different length) posted on here, but following the steps of the answer ...
*Thursday, June 12, 2014 by Abby*

**physics**

A spring is stretched by 0.72 m from its orginal length with an external force of 10.5. What is the spring constant, k, of the spring?
*Thursday, June 12, 2014 by serina*

**physics**

A boy on ice skates is atationary on a frozen lake(no friction).He throws a package of mass 5kg at 4m/s horizontally east.the mass of the boy is 60kg.at the instant the package leaves the boy's hand,the boy starts moving. Calculate the magnitude of the velocity of the boy ...
*Thursday, June 12, 2014 by Philisiwe*

**Physics**

Three resistors of value 1.0 , 2.0 and 4.0 are connected in a parallel circuit with a 6.0 V battery. a) What is the total equivalent resistance? b) What is the across each resistor? c) The power delivered to the 4.0 resistor?
*Thursday, June 12, 2014 by Anonymous*

**Physics**

3) What is the emf of a battery with an internal resistance of 0.15 if the battery delivers 1.5 A to an externally connected 5.0 resistors?
*Thursday, June 12, 2014 by Anonymous*

**physics**

A 200 – W computer power supply is on 10 hours per day. If the cost of electricity is $0.15/kWh, what is the cost (to the nearest dollar) to run the computer every day for a year (365 days)?
*Thursday, June 12, 2014 by Anonymous*

**physics**

A nut-cracker has arms o.4mlong and a nut is plsaced 0.05 from the hinge. Calculate the resistance of the shell if it is broken by a force of 100N applied at the end of the cracker(assume that all the forces are parallel)
*Thursday, June 12, 2014 by benjieo*

**physics**

A pole AB of length 10m and weight 600N has its centre of gravity 4m from the end A, and lies on horizontal fround.calculate the force required to begin to lift the end.why would this force applied at the end A,not be sufficient to lift the end A?
*Thursday, June 12, 2014 by benjieo*

**physics**

A nut-cracker has arms o.4m long and a nut is placed 0.05m from the hinge. Calculate the resistance of the shell if it is broken by a force of 100N applied at the end of the cracker(Assume that all forces are parallel)
*Thursday, June 12, 2014 by benjieo*

**Physics**

A man was lost in the woods. He wanders 3 km north, then 7 km east, then 7 km south, then 4 km west. What is the magnitude and direction of his resultant displacement?
*Thursday, June 12, 2014 by Van*

**Physics **

Merry go round is push by a 100 kg man Radius is 2 m how much force is exerted. Maximum force in newtons
*Thursday, June 12, 2014 by Brett*

**physics**

A uniform ladder AB leans against a smooth vertical wall at an angle 60degree to the horizontal.the weight of the ladder is 200N. By taking moments about a suitable point,calculate the reaction at the wall
*Thursday, June 12, 2014 by benjieo*

**physics**

A pole AB of length 10m and weight 600N has its centre of gravity 4m from the end A,and lies on horizontal ground. Calculate the force required to beging tto lift the end. Why would this force applied at the end A not be sufficient to lift the end A
*Thursday, June 12, 2014 by benjieo*

**physics**

An aeroplane taking off from a field has a run of 500 meters. What is the acceleration and take off velocity if it leaves the ground 10 seconds after the start ?
*Thursday, June 12, 2014 by Sanya*

**physics**

A nut-cracker has arms o.4m long and a nut is placed 0.05m from the hinge. Calculate the resistance of the shell if it is broken by a force of 100N applied at the end of the cracker(Assume that all forces are parallel)
*Thursday, June 12, 2014 by benjieo*

**physics **

A uniform ladder AB leans against a smooth vertical wall at an angle 60degree to the horizontal.the weight of the ladder is 200N. By taking moments about a suitable point,calculate the reaction at the wall
*Thursday, June 12, 2014 by benjieo*

**physics(moment/equilibrium)**

A pole AB of length 10m and weight 600N has its centre of gravity 4m from the end A,and lies on horizontal ground. Calculate the force required to beging tto lift the end. Why would this force applied at the end A not be sufficient to lift the end A
*Thursday, June 12, 2014 by benjieo*

**physics**

a mass is thrown vertically upwards with an initial velocity of 30m/s. a second mass is dropped 0.5s later from directly above the height of 60m from the mass. when do they meet and at what height?
*Wednesday, June 11, 2014 by adii *

**Physics**

A 1.8 tonne railway truck moving at a speed of 3m/s up a steady incline comes to a stop after 45m. If the sum of the friction opposing the truck amounts to 80N What is the angle of elevation of the slope? I found Fg using m*g THen I tried using v^2=u^2 + 2as to find the ...
*Wednesday, June 11, 2014 by Random*

**physics**

98. On which of these hills does the ball roll down with increasing speed and decreasing acceleration along the path? (Use this example if you wish to explain to someone the difference between speed and acceleration.) 99. If you drop an object, its acceleration toward the ...
*Wednesday, June 11, 2014 by Becca*

**Physics**

The current in a river is 1.0 meters/second. Britney swims 300 meters against the current. If she normally swims with a speed of 2.0 meters/second in still water, how long does it take her to complete the trip?
*Wednesday, June 11, 2014 by LegitPhiz*

**PHYSICS**

for given angle of projection if time of flight is doubled horizontal range will increase to A FOUR TIMES B thrice C once D TWICE
*Wednesday, June 11, 2014 by AYESHA*

**PHYSICS**

ratio of average velocity and average and average speed
*Wednesday, June 11, 2014 by AYESHA*

**physics**

A body is to be projected at an angle with a velocity 24m/s just to pass over an obstacle 14m high at adistance of24m.then angle is what.
*Wednesday, June 11, 2014 by Anonymous*

**Physics**

A body is thrown vertically upward with initial velocity 9.8m/s what height it will attain ?
*Wednesday, June 11, 2014 by Dua Jawaid*

**PHYSICS**

ball is dropped from certain height another ball is projected horizontally from the same point . Which statement is correct A BOTH HIT GROUND AT SAME VELOCITY B BOTH HIT GROUND AT SAME SPEED C change of velocity during path for both balls is same D change of SPEED during path ...
*Wednesday, June 11, 2014 by AYESHA*

**physics**

The weightless strut in the figure below is not attached to the wall; it is prevented from falling only by friction. (Let w = 360 N, L = 5.25 m and h = 3.25 m.) (a) Find the magnitude of the force of friction between the wall and the strut. Correct: Your answer is correct. (b...
*Wednesday, June 11, 2014 by Anonymous*

**PHYSICS**

ball is dropped downwards. After 1 sec another ball is dropped from the same point . What is distance between them after 3sec A 25m B 20m C 50m D 9.8m
*Wednesday, June 11, 2014 by AYESHA*

**physics**

if a train at 72kmphr is to be brought to rest in a distance of 200 m then its retardation is A 20m/s^2 b 10m/s^2 c 2m/s^2 d 1m/s^2
*Wednesday, June 11, 2014 by AYESHA*

** physics**

a car travels first half distance between two places with average speed of 30 km per hour and remaining half with a speed of 50 km per hour what is the average speed of the car is A 37.5KM/hr B 10km/hr //c// 42km/hr D 40km/hr
*Wednesday, June 11, 2014 by AYESHA*

**Physics**

Hi, I need help with another question! A microwave transmitter emits waves towards a metal plate. The waves strike the plate and are reflected back along their path. I really wish I could put the diagram here but I don't think that's possible... The diagram shows 5 ...
*Wednesday, June 11, 2014 by Leiah_*

**Physics**

Hi! I need help with this question... A double slit experiment, using light of wavelength 600 nm, results in fringes being produced on a screen. The fringe separation is found to be 1.0 mm. When the distance between the double slits and the viewing screen is increased by 2.0 m...
*Wednesday, June 11, 2014 by Leiah_*

**physics**

a 150 metre long train crosses a bridge of length 250 metres in 25 seconds find its velocity
*Wednesday, June 11, 2014 by harish*

**physics**

A boy on a motor scooter is traveling at a velocity of 14.1 m/s when he applies his brakes in order to stop. How much time will it take him to stop if he slows down at a rate of 3.2 m/s2?
*Wednesday, June 11, 2014 by roger*

**physics**

A motorist is driving at a constant velocity of 28 m/s when he decides to pass a car that is in front of him. He accelerates at a rate of 2.5 m/s2 for 3.0 seconds while passing the car. What is his velocity at the end of the 3.0 seconds?
*Wednesday, June 11, 2014 by roger*

**physics**

A motorist is driving at a constant velocity of 28 m/s when he decides to pass a car that is in front of him. He accelerates at a rate of 2.5 m/s2 for 3.0 seconds while passing the car. What is his velocity at the end of the 3.0 seconds?
*Wednesday, June 11, 2014 by Anonymous*

**physics**

A student drops an object from a fourth floor window. The velocity of the object is measured at 29.28 m/s 3.0 seconds later. What is the acceleration of the object?
*Wednesday, June 11, 2014 by Anonymous*

**Physics**

The Achilles tendon is attached to the rear of the foot as shown in (Figure 1) . A person elevates himself just barely off the floor on the "ball of one foot." Assume the person has a mass of 65kg and D is twice as long as d. Find the tension FT in the Achilles ...
*Tuesday, June 10, 2014 by George*

**Physics**

What is the maximum tension possible in a 1.15 mm diameter nylon tennis racquet string? The ultimate tensile strength for nylon is 5.00×10^8N/m2.
*Tuesday, June 10, 2014 by George*

**Physics**

Help please How do the dark lines of an atom's absorption spectrum relate to the bright lines of its emission spectrum? A. The bright lines are at the same energies as the dark lines. B. The dark lines are at higher energies than the bright lines. C. The bright lines are ...
*Tuesday, June 10, 2014 by Me and I*

**physics**

A flat circular mirror of radius 0.150 m is lying on the floor. Centered directly above the mirror , at a height of 0.750 m, is a small light source. Calculate the diameter of the bright circular spot formed on the 2.90 m high ceiling by the light reflected from the mirror.
*Tuesday, June 10, 2014 by Meghan*

**LA**

For questions 17–19, refer to the passage below: Albert Einstein, a world-famous mathematician was born in Bavaria in 1879. He acquired Swiss nationality in 1901 and he began working at the Swiss patent office the next year. Einstein was however also publishing papers in ...
*Tuesday, June 10, 2014 by dfca*

**Physics**

Determine the acceleration of a 1500 kg automobile that rolls down an incline of 30° from the horizontal if a coefficient of friction between the tires and the incline is 0.12
*Tuesday, June 10, 2014 by Corey Brown*

**Physics**

Calculate the tension in the cable connecting the two masses. Assume all surfaces are frictionless.
*Tuesday, June 10, 2014 by Corey Brown*