Friday

May 6, 2016
**Physics**

A pendulum bob has a mass of 1kg. The length of the pendulum is 2m. The bob is pulled to one side to an angle of 10degree from the vertical. What is the velocity of the pendulum bob as it swings through it's lowest point? What is angular velocity?
*Thursday, March 10, 2016 by Sam*

**Physics**

A ball of mass 500g is kicked into the air at angle of 45degree. It reaches a height of 12m. What was it's initial velocity?
*Thursday, March 10, 2016 by Sam*

**Physics (Kinematics)**

In the same instant that a Porsche races past him at 130 km/h, a speed cop gets off his motorcycle, accelerates uniformly at 8 m/s^2, to catch the speedster. After 5 seconds the trafic officer reaches his top speed, which he then maintains until he reaches up to the car. How ...
*Thursday, March 10, 2016 by Jonathan Nokhoya*

**Physics**

An airplane pilot checks her instruments and finds that the air speed of the plane is 325 km/h. the instruments show that the plane is pointed in a direction (S 30 W). A radio report indicates that the wind velocity is 80 km/h (W). What is the velocity of the plane relative to...
*Thursday, March 10, 2016 by lomonoyan*

**physics**

A binary star consists of two dense sphereaty masses of 10rest power 30 kg and 2 x 10rest power 30kg. Whose centres are 10rest power7km apart and which rotate togethe with angula velocity w about an axis which intersects a line joining their centres - show that if the only ...
*Thursday, March 10, 2016 by ugochukwu*

**Physics**

A 30-gram bullet leaves a gun barrel with a speed of 230 m/s. (a) What work is done on the bullet while it is in the gun barrel? (b) If the gun is 0.60m long, what is the average force on the bullet?
*Thursday, March 10, 2016 by DeezNutz*

**Physics (Inside the atom)**

A sample of radioactive isotope I is to be used for medical diagnosis of the kidneys. The isotope has a half-life of 8.0 days, and the sample is required to have an activity of 8 x 10^5 per second at the time it is given to the patient. Calculate the mass of the I-131 present ...
*Thursday, March 10, 2016 by Hannah*

**Physics**

a speeding car is driving at 120 km/h when it passes a police cruiser that is driving at 100 km/h. One second later, the police cruiser accelerates uniformly at 15 km/h until it reaches a speed of 135 km/h. how long does it take the police cruiser to catch the car
*Thursday, March 10, 2016 by John*

**physics**

An object is placed (a) 6cm (b) 20cm from a thin convex lens of focal length 10cm. Determine the nature, position and magnification of the image in each case.
*Thursday, March 10, 2016 by ugochukwu*

**Physics**

a tennis ball has mass 0.045 kg and is hit at a speed of 120 km/h by the server. the opposing player hits the ball exactly back along the line of its trajectory giving the ball a new speed of 115 km/h. if the contact time between the racquet and the ball is 0.02s what is the ...
*Thursday, March 10, 2016 by Anonymous*

**Physics**

during a snowball fight two balls with masses of 0.28 and 0.75 kg, respectively , are thrown in such a manner that they meet head-on and combine to form a single mass. the magnitude of initial velocity for each is 15 m/s. what is the speed of the combined mass immediately ...
*Thursday, March 10, 2016 by Anonymous*

**Physics**

a 6 kg mass with an initial velocity of 7 i m/s collides and sticks to a 5 kg mass with an initial velocity of v j m/s. the direction of the final velocity of the two masses with respect to the direction of the x axis is -15 degrees. what is v?
*Thursday, March 10, 2016 by Anonymous*

**physics**

a)find the charge to mass ratio for an electron accelerated through 600v in a magnetic field of strength 45mT where the speed of the electrons is 1.4*10^7m/s b)what is the percentage difference b/n your result and the accepted ratio with the value q=1.6*10^-19C and m=9.11*10^-...
*Thursday, March 10, 2016 by ruth*

**Physics**

A police car approaches a large wall at 51m/s. Its siren emits a 980 Hz signal. What is the frequency of the reflected sound observed by the officer?
*Thursday, March 10, 2016 by maryam*

**physics**

an electron moves in the plane of paper toward the top of the page .a magnetic field is also in the plane of the page and directed toward the right .what is the direction of the magnetic force on the electron ?
*Thursday, March 10, 2016 by ruth*

**physics**

At what height above Earth's surface is the gravitational acceleration reduced from its sea-level value by 0.20%? At what height above Earth's surface is the gravitational acceleration reduced from its sea-level value by 2.0%? At what height above Earth's surface ...
*Thursday, March 10, 2016 by lizbeth*

**Physics**

Suppose a 300–g kookaburra (a large kingfisher bird) picks up a 84.0–g snake and raises it 2.30 m from the ground to a branch. How much work did the bird do on the snake? I know that W=deltaPE, and PE=mgh. I keep getting 1046.64. Please help!
*Thursday, March 10, 2016 by Emily*

**Physics**

a 45-kg box initially at rest is being pushed with a force of 950 N along a frictionless horizontal surface. What is the speed of the boz after traveling a distance of 2.0m
*Thursday, March 10, 2016 by Thea*

**Physics **

An image formed by a convex mirror (f = -24.0 cm) has a magnification of 0.150. Which way and by how much should the object be moved to double the size of the image?
*Thursday, March 10, 2016 by zhel *

**Physics**

Devise the series or parallel combination of 2 capacitances from the E6 series that gives the closest match to the capacitance 1.14 μF. Indicate the percentage error between the desired value and the value you obtain.
*Thursday, March 10, 2016 by Mike*

**Physics**

Someone please help. A radio needs to be tuned to a range of values between 526.5 - 1606.5 kHz. Choose a combination of inductor and variable capacitor values within a tuned circuit that would meet this requirement. Choose practical components from standard vendor web sites (e...
*Thursday, March 10, 2016 by Dan*

**Physics **

Nicole is late for work. She jumps in her car and drives to work in 3.5 minutes. Her work place is 3.85 km away from her house. The speed limit between home and work is 50 km/hour. Is Nicole speeding?
*Thursday, March 10, 2016 by Tom*

**Physics **

Juliet sits on her balcony while Romeo serenades her from the ground, 7.00m below. To win Juliet’s affection, Romeo throws Juliet a bouquet of roses. At what velocity must the roses be thrown if they are to reach Juliet on the balcony?.
*Thursday, March 10, 2016 by Tom*

**Physics **

Gary and Elaine are competing as a team in an orienteering event. They follow instructions telling them to go 50 m [N], 75 m [NE] and 100 m [30o E of S]. a) Calculate the total distance travelled b) Draw a vector diagram to determine the resultant displacement.
*Thursday, March 10, 2016 by Tom*

**physics **

An object of mass 10kg is drawn from height of 10cm. Find (g=10m/s) its kinetic energy on reading the ground.. Velocity before as it reaches the ground.
*Thursday, March 10, 2016 by pratheeksha *

**PHYSICS**

A CAR COVERED A DISTANCE OF 10m IN 5 s; ITS SPEED WILL BE?
*Thursday, March 10, 2016 by RUNALDO*

**physics**

the speed of light is measured to be 1.50*10^8 m/s in a sucrose water solution. calculate the refractive index of the solution. \
*Thursday, March 10, 2016 by ayesha*

**math111**

in a science class,65 student study physics while 40 study chemistry.if there are 93 student in the class,how many student study both physics and chemistry?
*Thursday, March 10, 2016 by james*

**Physics**

Consider a sound wave in air that has displacement amplitude 0.1mm.calculate the pressure amplitude for frequensis of: 1) 500 Hz 2) 20,000 Hz
*Thursday, March 10, 2016 by Megha*

**Physics**

Verify that the formula u(t)=Acos(ωo*t+Φ) is a solution to the differential equation for the mass on a spring, by plugging this expression for u(t) directly into the differential equation: d^2u/dt^2+ωo^2*u=0.
*Thursday, March 10, 2016 by Anonymous*

**Physics **

The melting point of aluminum is 660°C, its latent heat of fusion is 4.00 × 105 J/kg, and its specific heat is 900 J/kg • K. If 300 kJ of heat are added to 442 g of aluminum at 100°C, what is the final state of the system? That is, how much is liquid, how ...
*Thursday, March 10, 2016 by MB*

**physics**

A train is moving with a speed of 50 miles per hour. A man standing in the rear of a train car throws a ball toward the front of the train with a speed of 10 miles per hour. If a stationary observer outside the train sees this happen, what speed is the ball moving with? ...
*Wednesday, March 9, 2016 by cadey*

**Physics**

5. A grating with 400 lines per mm is illuminated with light of wavelength 600.0 nm. (a) Determine the angle at which the maxima are observed (b) Determine the largest order (n) that can be seen with this grating and this wavelength.
*Wednesday, March 9, 2016 by Luke*

**physics**

A charge q1 = 5 nC is located at the origin of xy copedinate system, and a charge of q2 = -2 nC is located on the y-axis at y =.30m. Find the components of the electric field and its magnitude and direction at a point P with coordinates (.40m, .30m).
*Wednesday, March 9, 2016 by micah*

**physics**

Three sheets of plastic have unknown indices of refraction. Sheet 1 is placed on top of sheet 2, and a laser beam is directed onto the sheets from above. The laser beam enters sheet 1 and then strikes the interface between sheet 1 and sheet 2 at an angle of 19.8° with the ...
*Wednesday, March 9, 2016 by James*

**physics**

Three sheets of plastic have unknown indices of refraction. Sheet 1 is placed on top of sheet 2, and a laser beam is directed onto the sheets from above. The laser beam enters sheet 1 and then strikes the interface between sheet 1 and sheet 2 at an angle of 19.8° with the ...
*Wednesday, March 9, 2016 by Anonymous*

**physics**

When you look through a 3.7 mm thick window comprised of a material whose refractive index is 1.59, by what time interval is the light you see delayed by having to go through glass instead of air? By how many wavelengths is it delayed, if its vacuum wavelength is 600 nm?
*Wednesday, March 9, 2016 by Anonymous*

**physics**

When you look through a 3.7 mm thick window comprised of a material whose refractive index is 1.59, by what time interval is the light you see delayed by having to go through glass instead of air? By how many wavelengths is it delayed, if its vacuum wavelength is 600 nm?
*Wednesday, March 9, 2016 by Anonymous*

**physics**

When you look through a 3.7 mm thick window comprised of a material whose refractive index is 1.59, by what time interval is the light you see delayed by having to go through glass instead of air?
*Wednesday, March 9, 2016 by Anonymous*

**Physics **

The momentum of a 12 kg dog racing to greet its owner is 37 kg m/s. What is the dog’s speed? is Pb-mbvb=(12)(37)=?
*Wednesday, March 9, 2016 by Reina Bonilla *

**physics**

When you look through a 3.7 mm thick window comprised of a material whose refractive index is 1.59, by what time interval is the light you see delayed by having to go through glass instead of air?
*Wednesday, March 9, 2016 by Anonymous*

**Probability**

The probability that a student passes a physics test is 2/3 and the probability that he passed both physics test and an english test is 14/15. The probability. The probability that he passes at least one test is 4/5. What is the probability that he passes the english test.
*Wednesday, March 9, 2016 by Ammu*

**Physics**

Many people mistakenly believe that the astronauts that orbit the Earth are "above gravity". Calculate g for space-shuttle territory, 206 kilometers above the Earth's surface. Earth's mass is 6e24 kg, and its radius is 6.38e6 m (6380 km). Your answer is what ...
*Wednesday, March 9, 2016 by Kevin*

**Physics**

Find the change in the force of gravity between two planets when the distance between them is decreased by a factor of 4.7
*Wednesday, March 9, 2016 by Kevin*

**physics**

A 50 kg sign is hanging from the ceiling .calculate the tension in the ropes?30 degree and 20 degree
*Wednesday, March 9, 2016 by mulaudzivhonani*

**physics**

a ball of 100g is thrown vertically upwards with an initial speed of 150km/h, calculate the time taken to return to the thrower
*Wednesday, March 9, 2016 by wisdom*

**physics**

At what height above Earth's surface is the gravitational acceleration reduced from its sea-level value by 0.20%? At what height above Earth's surface is the gravitational acceleration reduced from its sea-level value by 2.0%? At what height above Earth's surface ...
*Wednesday, March 9, 2016 by lizbeth*

**Physics**

A ball is dropped from a building, after 2 sec another ball is thrown downward. After 6 sec the second ball overtook the first ball. Is the second ball has greater acceleration than the first ball? Explain.
*Wednesday, March 9, 2016 by Leaha Angelina*

**physics**

Three charges, +2.5 micro coulomb, -4.8 micro coulomb and 6.3 micro coulomb, are located at (0.20m, .15m), (.50m, -.35m), and (-.42m,-.32m) respectively. What is the electric field at the origin?
*Wednesday, March 9, 2016 by micah*

**PHYSICS ( PERIODIC MOTION)**

A grandfather clock uses a physical pendulum to keep time. The pendulum consists of a uniform thin rod of mass M = 2.01 kg and length L = 0.19 m that is pivoted freely about one end, with a solid disk of mass 3M and a radius of L/4 attached to the free end of the rod. a) What ...
*Wednesday, March 9, 2016 by MUSTAFA GHANIM*

**PHYSICS ( PERIODIC MOTION)**

In a lab, a student measures the unstretched length of a spring as 12.9 cm. When a 113.6-g mass is hung from the spring, its length is 26.3 cm. The mass-spring system is set into oscillatory motion, and the student observes that the amplitude of the oscillation decreases by ...
*Wednesday, March 9, 2016 by MUSTAFA GHANIM*

**Physics**

Is Gc (32.2 lbmft/lbfs^2) equal to gravity? I think it is, but I'm kinda confused about the whole concept. Could someone explain it to me? Thank you very much.
*Wednesday, March 9, 2016 by Danny*

**physics**

Assumed that north is the y-direction and east the x-direction. You are piloting the boat that moves at a constant speed of 10 km/hr relative to the water beneath it. 1) On a body of still water, you point your boat due north for 2hr, then turn due east and continue for ...
*Tuesday, March 8, 2016 by anna*

**Physics**

A Ferris wheel, 24.0 m in diameter, rotates once every 12.5 s(see the diagram.) What is the fractional change in a person'sapparent weight (a) at the top, and (b) at the bottom, as comparedto her weight at rest?
*Tuesday, March 8, 2016 by Jade*

**Physics**

The ability to hear a “pin drop” is the sign of sensitive hearing. Suppose a 0.55-g pin is dropped from a height of 28 cm, and that the pin emits sound for 1.5s when it lands. Assuming all of the mechanical energy of the pin is converted to sound energy, and that ...
*Tuesday, March 8, 2016 by Cameron Arnold*

**Physics **

samuel drives his bicycle east at a velocity of 10.0 m/s. he then increases his speed in the same direction to 25.0 m/s in 3.50 s. what is his average speed
*Tuesday, March 8, 2016 by Tristan*

**physics**

Consider the hip joint. The bones are normally not in direct contact , but instead are covered with cartilage to reduce friction. The space between them is filled with synovial fluid, which reduces the friction further. Due to this fluid, the coefficient of kinetic friction ...
*Tuesday, March 8, 2016 by vanessa*

**Physics 1**

A 50 kg cannonball hits a war tank vehicle of 12,000 kg that is initially at rest. The cannonball embeds in the tank and both move at the same velocity for 50 cm until they both come to a rest. What is the initial velocity of the cannonball if the coefficient of friction ...
*Tuesday, March 8, 2016 by David*

**Physics 1**

A golf ball of mass 125 g hits a billiards ball of mass 172.5 g that is initially at rest. After the collision, the golf ball moves to the right at a speed of 10 cm/s. The billiards ball moves to the left with a speed of 58 cm/s. (a) What was the velocity of the golf ball ...
*Tuesday, March 8, 2016 by David*

**Physics **

A 5.0-g bullet traveling horizontally at an unknown speed hits and embeds itself in a 0.195-kg block resting on a frictionless table. The block slides into and compresses a 180-N/m spring a distance of 5.0×10^−2 m before stopping the block and bullet.
*Tuesday, March 8, 2016 by Samir Patel*

**Physics**

A wire is made of a material with a resistivity of 2.08184 × 10−8 Ω · m . It has length 4.42917 m and diameter 0.6763 mm . What is the resistance of the wire? Answer in units of Ω. Would you just use the equation R = PL /a?
*Tuesday, March 8, 2016 by Jeff*

**Physics HW Plz help**

If a wave’s third harmonic has a frequency of 24 Hz, what is its natural (fundamental) frequency and what is the frequency of H6?
*Tuesday, March 8, 2016 by Student Lexi *

**physics**

The displacement of a particle is given by S = a+bt+ct^2. Deduce the dimensions of the constants,a,b,and c appearing in the question.
*Tuesday, March 8, 2016 by daniel*

**AP Physics**

Two speakers, one directly behind the other, are each generating a 406-Hz sound wave. What is the smallest separation distance between the speakers that will produce destructive interference at a listener standing in front of them? Take the speed of sound to be 344 m/s.
*Tuesday, March 8, 2016 by Kevin*

**physics**

Two objects of masses m1 = 0.58 kg and m2 = 0.92 kg are placed on a horizontal frictionless surface and a compressed spring of force constant k = 300 N/m is placed between them as in figure (a) shown below. Neglect the mass of the spring. The spring is not attached to either ...
*Tuesday, March 8, 2016 by sherry*

**physics**

A 12.0-g piece of clay is launched horizontally at a 102-g wooden block that is initially at rest on a frictionless horizontal surface and connected to a spring having spring constant 52 N/m. The piece of clay sticks to the side of the block. If the clay-block system ...
*Tuesday, March 8, 2016 by sherry*

**physics**

A projectile is launched from ground level at an angle of 45 degrees above the horizontal with a speed of 40m/s. It is aimed straight towards a high wall that is a horizontal distance of 120m away from the launch point. a) How much time will the projectile spend in the air ...
*Tuesday, March 8, 2016 by anna*

**Physics**

Consider the hip joint. The bones are normally not in direct contact , but instead are covered with cartilage to reduce friction. The space between them is filled with synovial fluid, which reduces the friction further. Due to this fluid, the coefficient of kinetic friction ...
*Tuesday, March 8, 2016 by tom*

**Physics grade 12**

Two point charges 2uC and 8uC are placed 12 cm apart. Find the position of the point where electric field resultant will be zero
*Tuesday, March 8, 2016 by Ibrahim *

**physics**

Consider the system shown in the diagram. The pulley is a uniform cylinder with mass m3 = 0.60 kg and radius R = 4.0 cm, the other two masses are m1 = 2.5 kg and m2 = 1.0 kg, and á = 30o. Assume the rope is massless, there is no slipping of the rope on the pulley, and ...
*Tuesday, March 8, 2016 by sam*

**Physics**

Consider the hip joint. The bones are normally not in direct contact , but instead are covered with cartilage to reduce friction. The space between them is filled with synovial fluid, which reduces the friction further. Due to this fluid, the coefficient of kinetic friction ...
*Tuesday, March 8, 2016 by tom*

**Physics**

A Stone Of Mass 1kg Is Dropped From Rest From A Window 20m Above The Ground.Another Stone Of Mass 0.5kg Is Dropped From A Height Of 5m Above The Ground . If Both Stones Are Dropped At The Same Time,find The Time Interval That That Elapses Between The Two Stones Hitting The ...
*Tuesday, March 8, 2016 by Lawrenty*

**Physics **

How long must a 25 degree ramp be to slow to a momentary stop a runaway truck moving along a truly horizontal highway at 85 miles per hour
*Tuesday, March 8, 2016 by Dennis*

**Physics**

A man walks 3km E and then 4km N. What is his resultant displacement?
*Tuesday, March 8, 2016 by Charles*

**Physics**

An airplane is heading 20degree north flying at 200km/hr relative to the air. Simultaneously the wind carries the plane 10degree, east of south at the speed of 60km/hr. (a) find the velocity of the plane relative to the ground. (b) find the component (east and south) of the ...
*Tuesday, March 8, 2016 by Charles*

**Physics**

Find the vector cross product of two vectors C=2i-j and D=i+2j-3k. What is the angle between the vectors
*Tuesday, March 8, 2016 by Charles*

**Physics**

Find the magnitude of the dot product of the two vectors B=6i+j+2k, D=-1+3j. What is the angle between B and D
*Tuesday, March 8, 2016 by Charles*

**Physics**

Consider two vectors one of magnitude 3 and the other 4 unit, which of the following is not correct? We can combine these vectors to yield a resultant of. A.7 B.5 C.1 D.0
*Tuesday, March 8, 2016 by Charles*

**Physics**

If D=7i-3j+2k and E=4i+5j-3k. Deduce angle between D and E
*Tuesday, March 8, 2016 by Charles*

**Physics**

If D=7i-3j+2k. Find the magnitude of D
*Tuesday, March 8, 2016 by Charles*

**Physics**

If D=7i-3j+2k and E=4i+5j-3k. Find the scalar product of D.E
*Tuesday, March 8, 2016 by Charles*

**Physics**

Find the sum of vectors A=5m<60degree and B=6m<130degree
*Tuesday, March 8, 2016 by Charles*

**physics**

You drop a rock into a well and count the seconds before you hear a splash. If you counted 10 seconds before you heard the splash, how deep is the well?
*Tuesday, March 8, 2016 by praveena*

**PHYSICS**

1. A 15 kg child sits in a swing that is attached in ropes 1.6 m long . Find the potential energy of the child relative to his lower position when the ropes (a) are horizontal (b) vertical and (c) make 30° with the horizontal. 2. A brick of mass 1.50 kg is placed on top of...
*Tuesday, March 8, 2016 by Camz*

**physics**

If the string on a violin is 25.4cm long and produces a fundamental tone of frequency of 440Hz, by how much must it be shortened to produce a fundamental tone of frequency of 523.3Hz. is there a specific formula to follow? like, how do you know what to do?
*Monday, March 7, 2016 by aaa*

**Physics**

A body is projected such that the horizontal range is twice the maximum height of projection. Find the angle of projection; and the time of flight if the velocity of projection is 5m/s
*Monday, March 7, 2016 by Charles*

**Physics**

What is the total time of flight of an object projected vertically upwards with a speed of 30m/s? (g=10m/s^2
*Monday, March 7, 2016 by Charles*

**Physics**

A car moving with a speed of 180km/h was brought uniformly to rest by the application of the breaks in 20s. How far did the car travel after the breaks were applied?
*Monday, March 7, 2016 by Coco*

**Physics**

A particle is at x=+5m at t=0, x=-7m at t=6s and x=+2m at t=10s. Find the average velocity of the particle during the intervals. (a) t=0 and t=6s (b) t=6s to t=10s (c) t=0 to t=10s
*Monday, March 7, 2016 by Coco*

**Physics**

A ball is thrown vertically upward with a velocity of 30m/s. Determine the maximum height reached
*Monday, March 7, 2016 by Vibes*

**Physics**

An aircraft flies 800km due east and then 600km due north. Determine the magnitude of it's displacement
*Monday, March 7, 2016 by Coco*

**Physics**

It took a car driver 30min to travel a distance of 50km. What is the average speed?
*Monday, March 7, 2016 by Coco*

**Physics**

Find the electric field at a point midway between two charges of +39.5 ✕ 10-9 C and +72.0 ✕ 10-9 C separated by a distance of 31.8 cm.
*Monday, March 7, 2016 by Anonymous*

**Physics**

An object 20cm high is placed 40cm from a lens of focal length 24cm. Calculate: a) The power of the Lens? b) The distance from the lens to the position of the image?
*Monday, March 7, 2016 by Joseph*

**physics**

the surface tension Y, of liquid depends on the density,P, acceleration of gravity,g, and the height, h. use the method of dimension to derive the actual relationship between these quantities
*Monday, March 7, 2016 by charles*

**Physics**

If s=at^2+bt+c, where s is distance and t is time, what will be the correct unit of a,b,c
*Monday, March 7, 2016 by Vibes*

**physics**

a sphere of radius r moving with velocity v through a fluid experiences a retarding force f given by F=6r^yv^zn^x where n is the viscosity of the liquid. use the method of dimensions to find the values of x,y,and z.
*Monday, March 7, 2016 by charles*

**physics**

What are the charges on and the potential difference across each capacitor in the figure if V = 13.2 V?
*Monday, March 7, 2016 by king*

**physics**

A 3.30-kg steel ball strikes a massive wall at 10.0 m/s at an angle of θ = 60.0° with the plane of the wall. It bounces off the wall with the same speed and angle (see the figure below). If the ball is in contact with the wall for 0.204 s, what is the average force ...
*Monday, March 7, 2016 by sherry*

**physics**

A 12.0-g piece of clay is launched horizontally at a 102-g wooden block that is initially at rest on a frictionless horizontal surface and connected to a spring having spring constant 52 N/m. The piece of clay sticks to the side of the block. If the clay-block system ...
*Monday, March 7, 2016 by sherry*