Saturday

August 1, 2015

August 1, 2015

**Physics**

A ball of mass 8 kg falls from rest from a height of 100 m. Neglecting air resistance, calculate its total energy after falling a distance of 40 m.
*Monday, January 5, 2015 by Bada*

**Physics**

A 70 kg person is riding on a frictionless skateboard at 5 m/s. A friend facing him throws a 5kg ball toward him at 20 m/s. What is his final speed after catch the ball?
*Monday, January 5, 2015 by vernon*

**Physics**

An aluminum measuring tape is correctly calibrated in metric units at exactly 0 degree Celsius. At is used to measure the distance between two lines on a floor, and the reading is 25.000 meters at a temperature of 30.000 degree Celsius. Determine the actual distance between ...
*Monday, January 5, 2015 by Shellie*

**physics**

the speed of a wave in a 4 m rope is 3.2 m/s. what is the frequency of the vibration required to produce a standing wave pattern with 1 antinode? 2 antinodes? 4 antinodes? please help!!! i don't understand how to do this
*Monday, January 5, 2015 by Isabelle*

**physics**

a pendulum 3m long is displaced at an angle of 40 degrees. What will be the maximum velocity of the pendulum when it is released to oscillate?
*Sunday, January 4, 2015 by lucy*

**physics**

a car rolls down a ramp 4m long that has angle of incline equal to 37 degrees. If the car starts from rest, what will be its velocity at the bottom of the ramp?
*Sunday, January 4, 2015 by lucy*

**physics**

a toy car rolls horizontally on to ramp that has total height of 1.28m. What minimum velocity will aloow the car to reach the top of the ramp?
*Sunday, January 4, 2015 by karson*

**physics**

what is the power if it takes 11s to drag the sled 80m?
*Sunday, January 4, 2015 by karson*

**Physics**

how much work is done to drag a 25kg sled 80m?
*Sunday, January 4, 2015 by NATHAN*

**physics**

The small piston of a hydraulic lift has a cross-sectional area of 3.6 cm2 and the large piston has an area of 86 cm2. What force F must be applied to the small piston to maintain the load of 52 kN at a constant elevation?
*Sunday, January 4, 2015 by justin*

**Physics**

a 4 kg object is taken to a planet that has 3 times the mass of earth and 1/2 the radius of earth. On this planet the mass of the object will be most nearly.. A. 12kg B. 3kg C. 48kg D. 4kg E. 24 kg
*Sunday, January 4, 2015 by NATHAN*

**physics**

A 3kg mass is attached to end of a light rod and made to move clockwise in a vertical circle of radius 2m and speed of 6m/s. The tension in the rod at the lowest point is most nearly A. 54N B. 84N C. 30N D. 24N E. 39N
*Sunday, January 4, 2015 by Demi*

**Physics**

A 2kg mass moving at 10m/s slows to speed of 4m/s while sliding across a rough horizontal surface. The work done by friction is most nearly A. 116j B -116J C. 84j D. -84j E. -16j
*Sunday, January 4, 2015 by Demi*

**PHYSICS**

A uniform plank with mass 20kg and length 12m extends 2m over the edge of a building. A 40kg crate is slid out on the plank. how far can the crate be pushed without toppling the plank? A. 0.5m B. 1m C. 1.25m D. 1.5m E. 2m
*Sunday, January 4, 2015 by Veronica*

**Physics**

A 3kg mass is sliding across a horizontal surface at a constant speed while being pulled by rope with tension 20N held at a 53 degree angle above the horizontal. The force of friction is most nearly A. 30N B. 12N C. 16N D. 20N E. 1N
*Sunday, January 4, 2015 by Veronica*

**physics**

Now how far the will the ball in the problem below will hit the ground? a. 10m b. 6.4m c. 9.6m d. 20m e. 140m a ball rolls off the table top 2m tall. with a velocity of 10m/s. with what speed will it strike the ground? V^2 = Vo^2 + 2g*h V^2=0^2+2*9.8*2 V^2=39.2^2 v=6.3m/s
*Sunday, January 4, 2015 by Jacob *

**physics**

explain why carrots look orange?
*Sunday, January 4, 2015 by sana*

**physics**

explain why carrots look orange
*Sunday, January 4, 2015 by sana*

**physics**

explain why carrots look orange
*Sunday, January 4, 2015 by sana*

**Physics **

An optical fiber is made of a clear plastic with index of refraction n=1.6, For what angles with the surface the light remain contained within the plastic guide?
*Sunday, January 4, 2015 by jo*

**physics**

A bungee jumper of mass 75 kg uses a bungee cord with a relaxedlength of 50 m and jumps from a bridge that is 170 m above the ground. What elastic force constant is necessary for the bungee cord in order for him to jump safely. I have no idea what to do or even start this ...
*Sunday, January 4, 2015 by Kim*

**physics**

A car moves from rest with a constant acceleration of 4m/s squared for 5s .IT then continues with the speed attained for10s and then accelerates at 2m/s squared for 10s.A/ SKETCH A SPEED TIME GRAPH FOR THE WHOLE MOTION GIVING YOUR VALUES ON BOTH AXES.B/CALCULATE THE AVERAGE ...
*Sunday, January 4, 2015 by Gabriella*

**Physics 11**

A 1.00 x 10^4 W electric motor is used to lift a 955 kg object vertically 25.0 m at a constant velocity in 45.0 s. What is the efficiency of the motor? I did P=W/t (1.00x10^4 x 45 =W) And got 4.50 x 10^5 Then I did Ep' = Ek 955 x 9.81 x 25 = 234213.75 But I wasn't sure...
*Sunday, January 4, 2015 by Allie*

**physics**

a ball rolls off the table top 2m tall. with a velocity of 10m/s. with what speed will it strike the ground? A. 10m/s B. 6.3m/s C. 16.3m/s D. 11.8m/s E. 139m/s
*Sunday, January 4, 2015 by Jacob *

**physics**

An acceptable unit for power would be A. kg-m/s B. kg-m-m/s/s/s C. N/s D. Kg-m-m/s/s E. J-s
*Sunday, January 4, 2015 by Jacob *

**physics**

a wooden block of mass equal to 15kg is pressed against a spring. The spring has constant of 225N/m. If the spring is compressed 0.15m, how fast will the block travel when released?
*Sunday, January 4, 2015 by Jacob *

**physics**

a toy car rolls horizontally on to a ramp that has a total height of 0.8m. what minimum velocity will allow the car to reach the top of the ramp/
*Saturday, January 3, 2015 by Jacob *

**Physics, Math, Aerospace, Engineering**

A de-orbit burn, similar (but not the same) to that presented in the previous math problem, has been performed. During this de-orbit burn a pre-calculated ∆V (delta V, change in velocity) of 99.1 meters per second will be used to decrease the Shuttle’s altitude from...
*Saturday, January 3, 2015 by Wolf*

**physics**

A 0.5 kg rock is projected from the edge of the top of a building with an initial velocity of 9.66 m/s at an angle of 41 degrees. The building is 10.1 m in height. At what horizontal distance, x, from the base of the building will the rock strike the ground? Assume the ground ...
*Saturday, January 3, 2015 by Kimberly*

**Physics**

How much force is required to accelerate a 1500kg car to a speed of 17m/s in a distance of 45m? Thank you.
*Saturday, January 3, 2015 by Steph*

**Physics**

A mass of 25kg is acted on by a force of 56N. If a friction force of 12N exists, find the acceleration of the mass. I have worked the following: a=F/M = 44/25 = 1.76 m/s2 Am I correct? Thank you.
*Saturday, January 3, 2015 by Steph*

**physics**

Three vectors are specified as A is 5 m at 45o north of east, B is 7 m at 60o east of south, and C is 4 m at 30o west to south. Find the magnitude and direction of their sum.
*Saturday, January 3, 2015 by saima*

**physics**

A man walks 5 m at 37 degree north of east then 10 m at 60 degree west of north.? calculate the magnitude and direction of his displacement.
*Saturday, January 3, 2015 by saima*

**physics**

a car is traveling 25 ns^-1 around a level curve of radius 120 m. what is the minimum value of the coefficient of static friction µs between the tires and the road to prevent the car from skidding
*Saturday, January 3, 2015 by saima*

**physics**

An object is thrown up from the top of building 50 m high. it rises to a maximum height of 20 m above the roof.? a) when does it land on the ground b) at what velocity does it land? c) what is its velocity 15m below the roof?
*Saturday, January 3, 2015 by saima*

**physics**

Determine the x and y components of the following vectors? a) P of length 5 m directed at 150 degree counter clockwise from the positive x axis b) Q of length 3.6 m directed at 120 degree clockwise from the positive y axis
*Saturday, January 3, 2015 by saima*

**physics**

a ship sails from a point at a distance of 4 km and a bearing of 40 degree noth of east relative to a lighthouse to a point 6 km from the lighthouse at 60 degree north to west. calculate a) the displacement b)the least distance between them
*Saturday, January 3, 2015 by saima*

**physics**

Three vectors are specified as A is 5 m at 45o north of east, B is 7 m at 60o east of south, and C is 4 m at 30o west to south.?Find the magnitude and direction of their sum.
*Saturday, January 3, 2015 by saima*

**physics**

A man walks 5 m at 37 degree north of east then 10 m at 60 degree west of north.? calculate the magnitude and direction of his displacement.
*Saturday, January 3, 2015 by saima*

**Physics**

You are going diving in a pool of fresh water. Your body can only take a total pressure on it of 2.0 atmospheres. How deep can you dive before your body can no longer take the pressure?
*Friday, January 2, 2015 by Christina*

**physics**

A toy boat has a volume of 0.0005m^3. It has a mass of 450 grams. How much of the boat is under fresh water?
*Friday, January 2, 2015 by Christina*

**Physics**

A hot air balloon of radius 12 meters has been heated so that the air inside has a density of 1.05 kg/m^3. What can the total load of the balloon be (mass of balloon itself plus cargo) if you need the balloon to accelerate into the air with an acceleration of 4 m/s^2?
*Friday, January 2, 2015 by Christina*

**Physics**

A place kicker must kick a football from a point 33.0 m (about 36 yd) from the goal. As a result of the kick, the ball must clear the crossbar, which is 3.05 m high. When kicked, the ball leaves the ground with a speed of 20.0 m/s at an angle of 48◦ to the horizontal. To...
*Friday, January 2, 2015 by Alyssa*

**physics**

Explain why a minibus is more likely to topple over when the roof rack is heavily loaded than when the roof rack is empty.
*Friday, January 2, 2015 by Anonymous*

**physics**

A ball is thrown horizontally from the top of a building 43.4 m high. The ball strikes the ground at a point 57.3 m from the base of the building. The acceleration of gravity is 9.8 m/s^2. a. Find the time the ball is in motion. Answer in units of s. b. Find the initial ...
*Friday, January 2, 2015 by Kimberly*

**physics**

An insect walks 50 cm in a straight line along a wall. if its horizontal displacement is 25 cm,? calculate its vertical displacement.
*Friday, January 2, 2015 by saima*

**physics**

a baseball is thrown at 30ms^-1. the batter hits it and gives it a velcoity of 40ms^-1 in the opposite direction. if the ball and bat are in contact for 0.04 s, what is the average acceleration of the ball during this interval?
*Friday, January 2, 2015 by saima*

**Physics 1**

a piece of stone was dropped from the top of the building. the stone took 10 s to hit the ground. what is the veocity of the stone just before it hit the ground?
*Thursday, January 1, 2015 by Marvin I. Rojas*

**Physics**

A force of 270N acts on a mass of 13.5kg for 13sec. Calculate a) the acceleration b) the final velocity c) the distance covered. a)F=m*a, so 270=13.5*a/13, answer 260m/s b)Not sure which formula. c)Formula d=v*t, once velocity is worked out in question b). I am not sure with a...
*Thursday, January 1, 2015 by Steph*

**physics**

A golfer takes two putts to get his ball into the hole once he is on the green. The ﬁrst putt displaces the ball 3.4 m east, and the second 6.55 m south. What displacement would have been needed to get the ball into the hole on the first putt. answer in units of m
*Thursday, January 1, 2015 by carlos*

**Physics**

A 6kg mass is acted on by a force for 60sec and acquires a speed of 10m/s. What is the value of the force? I have calculated this as below: F = ma Therefore F = 6*10/60 F=1N Am I on the correct path? Thank you kindly
*Thursday, January 1, 2015 by Steph*

**Physics**

A block and tackle with a velocity ratio of 5 is used to raise a mass of 25kg through a vertical distances of 40cm at a steady rate.if the effort is equal to 60N,determine.(a)The distance moved by the effort.(b)The workdone by the effort in lifting the load.(c)The loss in ...
*Thursday, January 1, 2015 by Rose*

**Physics**

What force is required to give a 1kg body a velocity of 5m/s after acting for 5sec? I know I can use F=mxa What do I do with the 5sec? Thanks
*Thursday, January 1, 2015 by Steph*

**physics**

A stone is thrown into water pond forming 10 waves in 5 seconds. The diameter of the first crest is 13 m and the diameter of the last crest is 4m. Find a.the periodic time b.the frequency c.the wave length d.the wave velocity
*Thursday, January 1, 2015 by jo*

**physics**

A ball strikes against the floor and returns with double velocity.In which type of collision is it possible?
*Thursday, January 1, 2015 by Anonymous*

**physics**

A car moves at a constant speed of 60 km/hr for 1 km and 40 km/hr for next 1 km. What is the average speed of the car ?
*Thursday, January 1, 2015 by sana*

**physics**

to view full image of an object 160 cm high, the minimum size of the plane mirror required is?
*Wednesday, December 31, 2014 by GM Chandio*

**Physics**

1) On the construction site an electric crane is used to lift materials to the 10th floor. A 180 kW motor requires 2.0 minutes to lift a 10500 kg load if bricks 218 m. How efficient is the crane? 2. Burning 1.0 kg of coal releases 33 MJ of energy. This energy is converted into...
*Wednesday, December 31, 2014 by Lucina*

**physics**

10. A 2-kg object is moving at 3m/s. A 4-N force is applied in the direction of motion and then removed after the object has traveled an additional 5m. The work done by this force is: A. 12 J B. 15 J C. 18 J D. 20 J E. 38 J ans: D 11. A sledge (including load) weighs 5000 N. ...
*Wednesday, December 31, 2014 by Anonymous*

**Physics**

Starting from Newton’s law of universal gravitation, show how to find the speed of the moon in its orbit from the earth-moon distance of 3.9 × 108 m and the earth’s mass. Assume the orbit is a circle. So I calculated this and got 1.0 km/s, I was just wondering ...
*Wednesday, December 31, 2014 by Marie*

**Physics**

What is the orbital velocity of the Earth around the Sun, assuming the Earth takes a perfectly circular orbit around the Sun? What would be the centripetal acceleration of the Earth around the Sun? (I have no clue :() From my textbook I found out that Earth has a mass of 5....
*Wednesday, December 31, 2014 by Deyves*

**physics**

a battery has an e.m.f of 6 volts and an internal resistance of 0.4 ohm.it is connected to a 2.6 ohm resistor through a SPST{single pole,single throw}switch.when the switch is closed,the potential difference between the terminals of the battery is,involts?
*Wednesday, December 31, 2014 by komal yaseen*

**physics**

two forces of the same magnitude act at a point.the square of their resultant is 3 times the product of their magnitudes.the angle between them is?
*Wednesday, December 31, 2014 by komal yaseen*

**physics**

2.4 ampere current is flowing in a wire .how many electrons pass a given point in the wire in one second if the charge on an electron is 1.6x10 power -19 couloms.
*Wednesday, December 31, 2014 by komal yaseen*

**physics**

a toroid has 3000 turns. the inner and outer diameter are 22 cm and 26 cm. what is the flux density inside the core when there is a current of 5 amperes?
*Wednesday, December 31, 2014 by komal yaseen*

**physics**

the resistance of a platinum resistance thermometer is 200.0 ohm at o degree centigrade and 257.6 ohm when immersed in hot bath,what is the temperature of the bath when 'alpha' for platinum is 0.00392degree centigrade inverse.
*Wednesday, December 31, 2014 by komal yaseen*

**physics**

A locomotive is running at a constant speed of 100 km/ h. The diameter of driving wheels is 1.8 m. The stroke of the piston of the steam engine cylinder of the locomotive is 600 mm. Find the centripetal acceleration of the crank pin relative to the engine frame.
*Wednesday, December 31, 2014 by joel*

**physics**

A flywheel is making 180 r.p.m. and after 20 seconds it is running at 140 r.p.m. How many revolutions will it make, and what time will elapse before it stops, if the retardation is uniform ?
*Wednesday, December 31, 2014 by joel*

**physics**

what will be the centipetal acceleration on a man whose mass is 80 kg,when resting on a ground at the equator if the radius of the earth'R' is 6.4x10 power 6 meter.
*Wednesday, December 31, 2014 by komal*

**physics**

the speed of an object at the end of 4 successive seconds is 20,25,30 and 35 meters per second,respectively.the acceleration of this object is?
*Wednesday, December 31, 2014 by komal*

**physics**

a ball of weight 200 grams,is tied to the end of a cord and whirled in a horizontal circle of radius 0.6 m.if the ball makes five complete revolutions in 2 seconds,what will be the linear speed of the ball?
*Wednesday, December 31, 2014 by komal*

**physics**

A cage descends a mine shaft with an acceleration of 0.5 m/s2. After the cage has travelled 25 metres, a stone is dropped from the top of the shaft. Determine : 1. the time taken by the stone to hit the cage, and 2. distance travelled by the cage before impact.
*Wednesday, December 31, 2014 by joel*

**physics**

What is the mass if an elephant that has 45,000 J when it is moving 5.0 m/s
*Tuesday, December 30, 2014 by Mackenzie*

**Physics**

Initially sliding with a speed of 2.5 m/s, a 2.0 kg block collides with a spring and compresses it 0.35 m before coming to rest. What is the force constant of the spring?
*Tuesday, December 30, 2014 by Caleb *

**physics**

How much thrust is required to launch a 5 kg bottle rocket with an upward acceleration of 6.4 m/s2? I've gotten 32 because F=MA but I don't understand how to account for gravity. Please help!
*Tuesday, December 30, 2014 by mack*

**physics**

a rock is dropped from a high brige.at the end of 3 seconds of free fall the speed of the rock is:[in centimeters per second,g=10 m/second square]
*Tuesday, December 30, 2014 by komal*

**physics**

Given that an iron ball falls in glycerine contained in a jar where the viscous force F depends on terminal velocity V radius R of the ball and the coefficient of viscosity obtain and name the mathematical expression suitable for the relationship btw the parameter if the ...
*Tuesday, December 30, 2014 by holamyde*

**physics**

Two carts are in contact on a horizontal frictionless surface. Cart 'A' has a mass of 3 kg, and cart 'B' a mass of 2 kg. (a) Find the force F on 'A' needed to give the two carts an acceleration of 0.8 m/sec2 . What is then the force exerted on 'B&#...
*Tuesday, December 30, 2014 by Anonymous*

**Physics**

Hi! Would one of you please check my work? Thanks! ( I used significant digits, by the way) A student throws a 5.00 kg steel shot directly upwards so that it leaves his hand when it is 2.00 m above the ground. If its velocity is 0.15 m/s when it leaves his hand, calculate: 1....
*Monday, December 29, 2014 by Lucina*

**Physics **

The work W0 accelerates a car from 0 to 20 km/h. How much work (in terms of W0) is required to accelerate the car from 20 km/h to 100 km/h?
*Monday, December 29, 2014 by Caleb *

**I guess this is physics related?**

What is the biggest source of error in measuring the acceleration of a ball down a ramp? knowing the length of the ramp accurately measuring the time knowing the height of the ramp knowing the mass of the ball****
*Monday, December 29, 2014 by Robert*

**Physics~ ONE MOREE**

Which of the following must the investigator measure during an experiment? independent variable dependent variable <<<<< controlled variable
*Monday, December 29, 2014 by May*

**So what about this one bob? Physics**

Which of the following is closer to a guess? hypothesis<<<<< law question theory
*Monday, December 29, 2014 by May*

**Physics**

Which of the following statements is true? A hypothesis always leads to a theory which leads to a law. A hypothesis always leads to a law which leads to a theory. A hypothesis must lead to a theory only. A hypothesis can lead to either a theory or a law. <<<<<&...
*Monday, December 29, 2014 by May*

**physics**

A 5kg block is placed on an inclined plane raised to an angle with it just started to slip down. if its coefficients of friction is 0.3 calculate. and the speed of the block up to the plane if it is being pull up by a force of 30N
*Monday, December 29, 2014 by holamyde*

**physics**

the speed of an object at the end of 4 successive seconds is 20,25,30 and 35 meters per second,respectively.the acceleration of this object is?
*Sunday, December 28, 2014 by komal yaseen*

**physics**

a man having a mass of 60 kg exerts a horizontal force of 200 newton in pushing a 90 kg object a distance of 60 meters along horizontal floor. he does this at constant velocity in 3 seconds.the weight of this man is[in newton,taking g =10m/s square]
*Sunday, December 28, 2014 by komal yaseen*

**physics**

How to make a project based on physics laws
*Sunday, December 28, 2014 by pavithran*

**Physics**

Hello! A falling piano reaches a velocity of 120 km/h. Find the kinetic energy if the mass of the piano is 357 kg. Ek= 1/2mv^2 Ek= 1/2(357)(33m/s)^2 Ek= 194386.5 J The problem is that my answer key has the answer 208kJ. What's my error? I have tried this problem many times...
*Saturday, December 27, 2014 by Lucina*

**Physics**

a 15000 kg airplane descends a vertical distance of 10.0 km over a horizontal distance of 80.0 km. What is the airplane's loss of potential energy. (I'm confused about the height) Ep=mgh m= 15000 kg g= 9.81 m/s^2 h=??
*Saturday, December 27, 2014 by Anonymous*

**physics**

When relaxed, an elastic cord has length L, cross section area A, mass M, and Young modulus Y. An object of mass m is hung from the ceiling using the cord. The system reaches a steady state. What is the longitudinal mass distribution lambda(z) of the stretched cord as a ...
*Saturday, December 27, 2014 by aviva*

**Physics**

A ball is thrown straight upward and returns to the thrower’s hand after 2.3 s in the air. A second ball is thrown at an angle of 60◦ with the horizontal. At what speed must the second ball be thrown so that it reaches the same maximum height as the first? The ...
*Saturday, December 27, 2014 by Lauren*

**PHYSICS**

An automobile accident investigator needs to determine the initial westerly velocity of jeep (m=1720 kg) that may have been speeding before colliding head-on with a Volkswagen (m=1510 kg) that was moving with a velocity of 75.7 km/h east. The speed limit on this road is 90 km/...
*Saturday, December 27, 2014 by Tony*

**Physics**

Station Math Two station astronauts will each perform two 8-hour EVAs within 13 days to repair a damaged solar panel that was impacted by a micrometeoroid on the space station. What is the total amount of oxygen needed by the two astronauts to accomplish this? Please put your ...
*Saturday, December 27, 2014 by Allison*

**physics**

a vertical object placed on a bench is observed to have three shadows of different sharpness,in different directions.explain tha observation
*Friday, December 26, 2014 by voxti*

**physics**

A golfer takes two putts to sink his ball in the hole once he is on the green. The ﬁrst putt displaces the ball 8.70 m east, and the second putt displaces it 6.04 m south. What displacement would put the ball in the hole in one putt? Answer in units of m and.......... ...
*Thursday, December 25, 2014 by Anonymous*

**physics**

Two bodies of mass 3kg and 4kg are suspended at the ends of massless string passing over a frictionless pulley .the acceleration system is
*Thursday, December 25, 2014 by prakhar*

**Physics**

1. What is happening to that air between the instruments and your ears? 2. How can you produce the change in the frequency? 3. Describe how the notes are produced in a violin?
*Wednesday, December 24, 2014 by Franny*

**Physics **

Two students (90.0 kg and 60.0 kg) on roller skates face-to-face push against each other. The 90.0 kg student moves at 5.0 m/s just after their hands lose contact. I figured out part A (final velocity of 60.0 kg student) to be 7.5 m/s backward. I need help with part B. (b) ...
*Wednesday, December 24, 2014 by Jason *

**Physics**

Problem: As you walk to class with a constant speed of 1.60m/s , you are moving in a direction that is 20.8∘ north of east. Part A How much time does it take to change your displacement by 22.0m east? Part B How much time does it take to change your displacement by 31.0m...
*Tuesday, December 23, 2014 by Big boss1*