Saturday

September 24, 2016
**physics**

a slingshot launches a rock straight upward at 25 m/s, how high does the rock go, how long is it in the air, what is the velocity and the acceleration of the rock at its highest point

*Saturday, August 27, 2016 by scott*

**physics**

a greyhound is capable of running at 40 mph, how many meters could the greyhound run in 3 minutes at this speed, how many seconds would it take the greyhound to run 1 km at this speed

*Saturday, August 27, 2016 by scott*

**Physics. Pleaseee helpppp**

Four electrons are located at the corners of a square 10.0nm on a side, with an alpha particle at its midpoint. How much work is needed to move the alpha particle to the midpoint of one of the sides of the square?

*Saturday, August 27, 2016 by Nanny*

**Physics**

A piece of wood of mass 60kg and density 600kg/m3 flows in water of density of 1000kg/m3.calculate (a) volume of water that the wood displaced (b) the fraction of volume of mass and water

*Saturday, August 27, 2016 by Pauliho*

**physics **

what change in velocity would be produced on a body of mass 4kg, if a contact force of 16N act on it for 2sec.

*Saturday, August 27, 2016 by sanusi *

**Physics **

A pebble is dropped from rest from the top of a tall cliff and falls 4.9meters after 1 second has elapsed. How much further does it drop in the next 2 seconds?

*Friday, August 26, 2016 by Hiba*

**Physics**

A heavy rainstorm dumps 1.0 cm of rain on a city 8 km wide and 9 km long in a 2 hour period. How many metric tons (1 metric ton = 10^3 kg) of water fell on the city? (1 cm^3 of water has a mass of 1g = 10^-3 kg) What I have thus far: 72 km^2 x (1E^10 cm^2/1km^2) x (10^-3 kg/ ...

*Friday, August 26, 2016 by Anonymous*

**Physics**

How many metric tons (1 metric ton = 10^3 kg) of H2O fell on a city? (1cm^3 of H2O has a mass of 1g = 10^-3 kg) Thus far I have: 10^-3 Kg x (1 metric ton/10^3) but I don't understand the significance of adding 1 cm^3 to the problem.

*Friday, August 26, 2016 by Kaitlin*

**12th grade physics**

A boat pulled through a canal by horses walking parallel to the canal and exerting a force of 1000 N on a tow Rope 40 meters long. Is the distance from the boat to the horse track is 15 meters, what is the magnitude of the effective component pulling the boat forward

*Friday, August 26, 2016 by Daryione*

**physics**

round of the following digits- 3.65*105(upto are place of decimal) 0.882026(upto three significant figures) 311.299(upto four significant figures) 4.783(upto two significant figures)

*Friday, August 26, 2016 by yashaswi*

**Physics**

A water tank has a mass of 3.65 kg when empty and has a mass of 52.5 kg when filled to a certain level. What is the mass of water in the tank?

*Friday, August 26, 2016 by Faith *

**physics**

a ball is vertically upward with a velocity of 35m/s. how long will the ball reaches the ground?

*Friday, August 26, 2016 by jerson*

**Physics**

In a novel from 1866 the author describes a spaceship that is blasted out of a cannon with a speed of about 11.000 m/s. The spaceship is approximately 274 m long but part of it is packed with gunpowder, so it accelerates over a distance of only 213 m. What was the acceleration...

*Friday, August 26, 2016 by Geoff*

**Physics**

A racquet ball is struck in such a way that it leaves the racquet with a speed of 4.8 m/s in the horizontal direction. When the ball hits the court, it is a horizontal distance of 1.94 m from the racquet. Find the height of the racquet ball when it left the racquet. I need ...

*Friday, August 26, 2016 by Geoff*

**Physics I - Modern**

An electron with a speed of 0.988c is emitted by a supernova, where c is the speed of light. What is the magnitude of the momentum of this electron? Thanks for any help you can offer! I've tried so many things!

*Thursday, August 25, 2016 by Victoria*

**physics**

a greyhound is capable of running at 40 mph how many meters could the greyhound run in 3 minutes at this speed, how many seconds how many seconds would it take the greyhound to run 1 km at this speed

*Thursday, August 25, 2016 by bryan *

**physics**

A rock is thrown straight up with an initial velocity of 15m/s. ignore the effect of air resistance , how high will the rock rise ?

*Thursday, August 25, 2016 by Mahmoud*

**Physics**

Space explorers discover an 8.7×10^17kg asteroid that happens to have a positive charge of 4400 C. They would like to place their 3.3×10^5kg spaceship in orbit around the asteroid. Interestingly, the solar wind has given their spaceship a charge of -1.2C. What ...

*Thursday, August 25, 2016 by Brittany*

**physics**

A ball is thrown upward into the air with a speed of 15m/s. At what times does the ball pass a point 8 meters above the person's hand? 8m=-0.5(9.8)(t) t=1.8 seconds Is that correct?

*Thursday, August 25, 2016 by Chelsea Woodard*

**Physics **

An electric motor runs at a constant rotational frequency of 3000 r/min and has the load of 75 Nm and a 5,0 Nm extra load of friction and gear. The efficiency of the motor is 78%. a) What is the input power of the motor? b) What is the work done by the motor in 24 hours and c...

*Thursday, August 25, 2016 by Anonymous*

**physics**

A train moving with speed 72 km h−1 emits a whistle of frequency 600 Hz. A person is standing stationary on the platform. Calculate the frequency heard by the person if the train (i) approaches and (ii) recedes away from the listener.

*Thursday, August 25, 2016 by bharat*

**Physics**

Power of a car weighing 1200kg is 134.05hp and its efficiency is 90%. How long will it take to raise of the car to 20m/s from rest. solution:v2=u2+2as 400=2as as=200 real power=13.05hp =100001.3W effective power=90001.17W Power=W/t =mas/t =1200*200/t t=90001.17/240000 =2.67s ...

*Thursday, August 25, 2016 by RBAS*

**physics**

A plane flies from base camp to Lake A, 260 km away in the direction 20.0° north of east. After dropping off supplies it flies to Lake B, which is 150 km at 30.0° west of north from Lake A. Graphically determine the distance and direction from Lake B to the base camp. ...

*Wednesday, August 24, 2016 by john*

**physics vectors**

While exploring a cave, a spelunker starts at the entrance and moves the following distances. She goes 75.0 m north, 250 m east, 109 m at an angle θ = 30.0° north of east, and 156 m south. Find the resultant displacement from the cave entrance. The figure below ...

*Wednesday, August 24, 2016 by john*

**physics vectors**

A plane flies from base camp to Lake A, 260 km away in the direction 20.0° north of east. After dropping off supplies it flies to Lake B, which is 150 km at 30.0° west of north from Lake A. Graphically determine the distance and direction from Lake B to the base camp. ...

*Wednesday, August 24, 2016 by john*

**PHYSICS**

A bucket containing cement has a mass of 3kg. One end of a rope is attached to the handle of the bucket and the other end is wound around a horizontally mounted cylinder on frictionless bearings. The mass of cylinder is 6kg and its radius is 0.10m. The moment of inertia of the...

*Wednesday, August 24, 2016 by Sarah*

**physics vectors**

In the figure below, a spider is resting after starting to spin its web. The gravitational force on the spider is 0.158 N on the junction of the three strands of silk. The junction is supported by different tension forces in the two strands above it so that the resultant force...

*Wednesday, August 24, 2016 by john*

**PHYSICS**

A BALL MOVES ROUND A CIRCLE WITH RADIUS OF 20CM CALCULATE THE DISTANCE

*Wednesday, August 24, 2016 by ORJINTA*

**physics vectors**

If vector A = (6.00 i -8.00 j) units, vector B = (-8.00 i + 3.00 j) units, and vector C = (25.0 i + 22.0 j) units, determine a and b such that (a vector A + b vector B + vector C= 0.) a=? b=?

*Wednesday, August 24, 2016 by john*

**Physics**

Starting from rest, a 2500 kg helicopter accelerates straight up at a constant 1.7 m/s2. What is the helicopter's height at the moment its blades are providing an upward force of 29 kN? The helicopter can be modeled as a 2.6-m-diameter sphere. How do you start this ...

*Wednesday, August 24, 2016 by Brittany*

**Physics**

please help me 1)In the movie The avengers, Captain America sees an alien speeder incoming. The speeder passes directly overhead at 3.65m. If he throws his shield straight up with a speed of 7.40 m/s from a height of 1.55 m above the ground (a) will the shied reach the speeder...

*Wednesday, August 24, 2016 by Kevin*

**physics**

A 500 car travelling at 45 km/hr towards west collides w/a 20000 kg truck travelling at 30 km/hr, 30 degrees south of west. if the two vehicle remain tangled together after collision, in what speed and in direction will they move?

*Wednesday, August 24, 2016 by Iker*

**physics**

A block of wood is 8.00cm long, 20.0cm high, and 0.10m wide. its mass is 1.00kg. what is its density in g/cm3?

*Wednesday, August 24, 2016 by Anonymous*

**physics**

A vertical container with base area measuring 12.3 cm by 13.7 cm is being filled with identical pieces of candy, each with a volume of 50.0 mm^3 and a mass of 0.0200 g. Assume that the volume of the empty spaces between the candies is negligible. If the height of the candies ...

*Wednesday, August 24, 2016 by jacob*

**Physics**

When observing a stem of coconut trees during sunshine,how the light cannot pass through the leaves of the coconut tree even though it is thin and it form shadow, whereas the stem allows the light to pass through them but their stem is thick and how possible this could be??

*Wednesday, August 24, 2016 by Emitai Maiwelagi*

**Physics**

Totally confused on this question, Please help. 1)In the movie The avengers, Captain America sees an alien speeder incoming. The speeder passes directly overhead at 3.65m. If he throws his shield straight up with a speed of 7.40 m/s from a height of 1.55 m above the ground (a...

*Wednesday, August 24, 2016 by Kevin*

**physics vectors**

A snow-covered ski slope makes an angle of θslope = 34.0° with the horizontal. When a ski jumper plummets onto the hill, a parcel of splashed snow is thrown up to a maximum displacement of 1.10 m at θsnow = 24.0° from the vertical in the uphill direction as ...

*Tuesday, August 23, 2016 by john*

**physics vectors**

Consider the two vectors A with arrow = 3 i − j and B with arrow = − i − 6 j. Calculate the directions of A with arrow + B with arrow and A with arrow − B with arrow. A with arrow + B with arrow ° (counterclockwise from the +x axis) A with arrow &#...

*Tuesday, August 23, 2016 by john*

**physics**

A plane flies from base camp to Lake A, 260 km away in the direction 20.0° north of east. After dropping off supplies it flies to Lake B, which is 150 km at 30.0° west of north from Lake A. Graphically determine the distance and direction from Lake B to the base camp. ...

*Tuesday, August 23, 2016 by john*

**physics**

Two trains 200m and 300m are running towards each other at 50km/hr and 40km/hr respectively and the distance between the two trains is 12km. In how many minutes will the two trains cross each other.?

*Tuesday, August 23, 2016 by Abul Qasim*

**Physics**

A ball thrown vertically upwards is caught by the thrower 8 seconds afterwards . (take g =10) When the ball is caught by the thrower: what is its displacement from the initial position? b) what is the initial velocity? c) To what height does the ball rise? d) With regard to (c...

*Tuesday, August 23, 2016 by Wawen*

**physics**

There are 6 resistor of resistance 1ohm

*Tuesday, August 23, 2016 by pratyush*

**Physics**

Find another velocity when horizontal range is equal and one velocity is 500m/s and angle is 30degrees

*Tuesday, August 23, 2016 by Brijtosh*

**physics**

the upthrust on a boat is 1000 N what is the weight of the boat

*Tuesday, August 23, 2016 by meenakshi*

**physics**

If your weight is 300 N what is the upthrust on you when you are floating in water

*Tuesday, August 23, 2016 by meenakshi*

**physics**

if the weight of the stone was 2 N and the upthrust was 1 N what weight would the force meter show?

*Tuesday, August 23, 2016 by meenakshi*

**Urgent help! Physics**

A ball is kicked into the air with a speed of 10m per second at angle of 60 degrees to the horizontal (take g=10). a) Calculate the horizontal and vertical speed of the ball b) Calculate the ball's time of flight c) Calculate the distance from the kicked point that the ...

*Tuesday, August 23, 2016 by Papsi*

**physics**

A uniform wooden plank 68cm long and weighing 38N rest horizontaly on two knife edges each 10cm from the ends of the plank. (1) What is the greatest land which applied at one end of the plank will not cause it to over turn. (2) what are the reactions of the support cohese a ...

*Tuesday, August 23, 2016 by Asare Joseph*

**physics**

A 1-kg mass hangs by a string from a disk with radius 4.6 cm which has a rotational inertia of 5 × 10-5 kg·m2. After it falls a distance of 0.8 meters, how fast is it going to the nearest hundredth of a m/s?

*Monday, August 22, 2016 by laaamaama*

**Physics**

wave traveling on a rope is given by y=0.25 sin(0.3 radX-40radt), where y and X is expressed in meter and t is in seconds. Determine a-Amplitude. B-frequency C-Direction of motion. e-Displacement at X=0.6 m and t=2.3 s.

*Monday, August 22, 2016 by Shehab*

**physics**

A 126 kg student sits on a chair which is solely supported by a solid 0.4 meter-long steel rod 0.81 cm in diameter. To the nearest micron (millionth of a meter), what is the change in length of the rod produced by the student's weight?

*Monday, August 22, 2016 by clache*

**physics**

In the figure below, the bar is 2.4 meters long and has a mass of 145 kg. To the nearest newton what is the tension in the wire?

*Monday, August 22, 2016 by clache*

**physics**

should the bulb of thermometer be completely immersed in boiling water to measure its boiling point

*Monday, August 22, 2016 by remya*

**physics**

A train starts from rest from a station with acceleration 0.2m/s2 on a straight track and then comes to rest after attaining maximum speed on another station due to retardation 0.4m/s2 .If total time spend is half an hour, then distance between two stations is_ ?

*Monday, August 22, 2016 by binalika *

**physics**

Why we feel pain don't having sweater and not feel pain having sweater by beating with a stick ?

*Monday, August 22, 2016 by wajdan*

**physics**

how scientists inventions are effecting the environment?

*Monday, August 22, 2016 by esha*

**Physics**

A flowerpot falls from a windowsill 25.0 m above the sidewalk. A. How fast is the flowerpot moving when it strikes the ground?? B. How much time does a cat on the sidewalk below have to move out of the way before the flowerpot hits the ground? (Please answer with step by step ...

*Sunday, August 21, 2016 by Maggie*

**Physics**

An arrow is shot straight up from the edge of a cliff with an initial velocity of 50 ft/s. Answer the following questions using English units. The acceleration due to gravity has a magnitude of 32.2 ft/s. A. Find the time to reach the highest point. (please use step by step ...

*Sunday, August 21, 2016 by Maggie*

**Physics **

A robot probe drops a camera off of the rim of a 239 m high cliff on Mars, where the free-fall acceleration is -3.7 m/s^2. A. Find the time required for the camera to reach the ground. B. Find the velocity with which it hits the ground.( shown work will be appreciated)

*Sunday, August 21, 2016 by Maggie*

**Physics**

An arrow is shot straight up from the edge of a cliff with an initial velocity of 50 ft/s. Answer the following questions using English units. The acceleration due to gravity has a magnitude of 32.2 ft/s. A. Find the time to reach the highest point. B. Find the displacement at...

*Sunday, August 21, 2016 by Maggie*

**physics**

you walk 95.0 m at a speed of 1.26 m/s and then run 95.0 m at a speed of 3.61 m/s. what is the average velocity?

*Sunday, August 21, 2016 by karen*

**physics .Henry,Damon,Steve,Saed,bobpursley, And This is my question every one**

A ball is thrown straight up by a passenger in a train that is moving what a constant velocity. Where would the ball land —back in his hands, in front of him, or behind him? Does your answer change if the train is accelerating in the forward direction? if yes, how?

*Sunday, August 21, 2016 by himel*

**physics .Henry,Damon,Steve,Saed,bobpursley, And This is my question every one**

Two cannonballs are shot in sequence from a can-non, into the air, with the same muzzle velocity, at the same launch angle. Based on their trajectory and range, how can you tell which one is made of leand and which one is made of wood. If the same cannonballs where launched in...

*Sunday, August 21, 2016 by himel*

**physics .Henry,Damon,Steve,Saed,bobpursley, And This is my question every one**

A rocket-powered hockey puck is moving on a (friction-less) horizontal air-hockey table. The x- and y-components of its velocity as a function of time are presented in the graphs below. Assuming that at t=0 the puck is at (X0,Y0)=(1,2), draw a detailed graph of the trajectory ...

*Sunday, August 21, 2016 by himel*

**physics .Henry,Damon,Steve,Saed,bobpursley, And This is my question every one **

Same rental cars have a GPS unit installed, which allows the rental car company to check where you are at all times and thus also know your speed at any time. One of these rental cars is driven by an employee in the company's lot and during the time interval from 0 to 10s...

*Sunday, August 21, 2016 by himel*

**physics**

1. If one point charge is located at each corners of a right triangle, where q1=q3= 5.0μC, q2= 2.0 μC, and a= 0.10 m. Find the resultant force felt by the third charge.

*Sunday, August 21, 2016 by oishee*

**Physics**

At the beginning of a roller coaster ride the car is staionary at the top of a 30m high hill and then begins to fall. Neglect any resistive forces. Calculate the speed of the car when it reaches the top of the second hill on the roller coaster. The second hill has abheight of 12m

*Saturday, August 20, 2016 by Maddi*

**physics**

a boy pulls a 15 kg over level ground by a rope with a force of 50 newtons at 30 degrees above the horizontal, the coefficients of friction between the box and the ground are 0.3 and 0.4, calculate the normal force exerted on the box to the ground, calculate the acceleration ...

*Saturday, August 20, 2016 by bryan*

**physics**

a 75kg person is standing on a scale in an elevator, the scale gives a readout in newtons(you have to use a free body diagram)determine the reading on the scale in newtons in each of the following situations, when the elevator is not moving, the elevator is moving upward at 2...

*Saturday, August 20, 2016 by bryan*

**PHYSICS ASAP REPLY**

What is the difference between a hydrogen filled balloon and an air filled balloon moving in air? please answer. THe question is from the chapter PRESSURE.

*Saturday, August 20, 2016 by A GOODSTUDENT*

**Physics**

A man uses a crowbar 1.5 meters long to lift a rock weighing 600N (Newtons). If the fulcrum is 0.50 Meter fromthe end of the bar touching the rock,how much effort The man should apply?

*Saturday, August 20, 2016 by Hasan nagra*

**PHYSICS pressure**

What is the difference between a hydrogen filled balloon and an air filled balloon moving in air?

*Saturday, August 20, 2016 by A GOODSTUDENT*

**PHYSICS topic is pressure**

Why does a person feel difficult to breathe when he is in a deep well? Please answer!!!

*Saturday, August 20, 2016 by helpneededstudent*

**Physics**

a stone drops from the edge of the roof. it crosses a window 2m long in 0.1sec. how much time does the stone take to reach the lower end of window from roof?

*Saturday, August 20, 2016 by RHYTHUM*

**physics**

how much work is done when 100 kg lifted 5 meters above the ground

*Friday, August 19, 2016 by sol*

**physics**

The force exerted by two identical point charges on each other is 0.21 N. (a) Find the magnitude of the charge on each point charges.

*Friday, August 19, 2016 by electric charge and electric field*

**Physics**

Consider the box being pulled across the horizontal surface again. If the box has a mass of 10kg, the coefficient of friction is 0.25,the distance that the box is pulled is 5m, the force is 150N and the angle is 30 degrees, ehat was the initial speed of the box if the final ...

*Friday, August 19, 2016 by Aishah*

**Physics**

A metro train starts from a station with an acceleration of 2 m/s2 for 8 seconds. It then runs for 12 seconds with the speed acquired. Finally, it retards at a uniform rate of 4 m/s2 and stops. Find the distance travelled.

*Friday, August 19, 2016 by Iffath*

**Physics**

A particle covers an angle of 120¡ã while moving along the circumference of a circle. Find distance and displacement.

*Friday, August 19, 2016 by Prabhat*

**physics**

a body is at equilibrium under the action of three forces.one force is 10N acting due east and one is 5N in the direction 60¡ã northeast . what is the magnitude and direction of the third force

*Friday, August 19, 2016 by hamza*

**physics**

If half life of iodine 131 is 8 days, how much from 32g remain after 40 days (5 half lives).

*Friday, August 19, 2016 by henry*

**Physics **

Heat of 30 kcal is supplied to a system and 4200j of external work is done on the system so that it's volume decreases at constant pressure.what is the change in its internal energy (J=4200 j/kcal)

*Thursday, August 18, 2016 by Shaik Tanaaz *

**physics**

A spelunker is surveying a cave. She follows a passage 140 m straight west, then 250 m in a direction 45∘ east of south, and then 280 m at 30∘ east of north. After a fourth unmeasured displacement, she finds herself back where she started. for the last displacement...

*Wednesday, August 17, 2016 by welp*

**Physics**

A ball is thrown vertically upwards from the ground and it reaches a height of 20m. Calculate the speed the ball had when it was launched. I don't know how to solve this due to the fact that in the problem we only have the height as data , not even mass.

*Wednesday, August 17, 2016 by Naty*

**Physics**

A particle executing simple harmonic motion of amplitude 5 cm and period 2 s. Find the speed of the particle at a point where its acceleration is half of its maximum value

*Wednesday, August 17, 2016 by Anushka*

**physics**

calculate the escape velocity of a satellite from the earth's gravitational field,if the radius of the earth is 6.4×10^6m

*Wednesday, August 17, 2016 by john*

**Physics**

the center of gravity of a 100-g stick is located at 50 cm mark and the stick is supported at 60cm. mark, Where must an 80g object be hung in order to have equilibrium?

*Wednesday, August 17, 2016 by Nelcilyn*

**physics question **

For a science fair competition, a group of high school students built a kicker -machine that can launch a golf ball from the origin with a velocity of 11.2m/s and initial angle of 31.5° with respect to the horizontal. a) Where will the golf ball fall back to the ground? b...

*Wednesday, August 17, 2016 by himel*

**physics question **

Your friends car is parked on a cliff overlooking the ocean on an incline that makes an angle of 17.0° below the horizontal. The brakes fail, and the car rolls from rest down the incline for a distance of 29.0m to the edge of the cliff, which is 55.0m above the ocean, and...

*Wednesday, August 17, 2016 by himel*

**physics question **

Same rental cars have a GPS unit installed, which allows the rental car company to check where you are at all times and thus also know your speed at any time. One of these rental cars is driven by an employee in the company's lot and during the time interval from 0 to 10s...

*Wednesday, August 17, 2016 by himel*

**physics question**

A man in search of his dog drives first 10 mi northeast, then 12 mi straight south, and finally 8 mi in a direction 30 degree north of west . What are the magnitude and direction of his resultant displacement?

*Wednesday, August 17, 2016 by himel*

**physics question**

In a projectile motion, the horizontal range and the maximum height attained by the projectile are equal . A) what is the launch angle? B) If everything else slays the same , how should the launch angle, ¦È0, of a projectile be changed for the range of the ...

*Wednesday, August 17, 2016 by himel*

**physics question **

A rocket-powered hockey puck is moving on a (friction-less) horizontal air-hockey table. The x- and y-components of its velocity as a function of time are presented in the graphs below. Assuming that at t=0 the puck is at (X0,Y0)=(1,2), draw a detailed graph of the trajectory ...

*Tuesday, August 16, 2016 by himel*

**physics question **

Two cannonballs are shot in sequence from a can-non, into the air, with the same muzzle velocity, at the same launch angle. Based on their trajectory and range, how can you tell which one is made of leand and which one is made of wood. If the same cannonballs where launched in...

*Tuesday, August 16, 2016 by himel*

**physics question **

A ball is thrown straight up by a passenger in a train that is moving what a constant velocity. Where would the ball land —back in his hands, in front of him, or behind him? Does your answer change if the train is accelerating in the forward direction? if yes, how?

*Tuesday, August 16, 2016 by himel*

**physics math**

MULTIPLE -CHOICE QUESTION A baseball is launched from the bat at an angle θo = 30° what respect to the positive x-axis and with an initial speed of 40 m/s ,and it is caught at the same height from which it is was hit. Assuming ideal projectile motion (positive y-axis ...

*Tuesday, August 16, 2016 by himel*

**physics math**

A cruise ship moves southward in still water at a speed of 20.0 km/h, while a passenger on the deck of the ship walks toward the east at a speed of 5.0 km/h .The passengers velocity with respect to Earth is?

*Tuesday, August 16, 2016 by himel*

**physics math**

A Projectile is launched from the top of a building with an initial velocity of 30m/s at angle of 60° above the horizontal. The magnitude of its velocity at t= 5 s after the launch is

*Tuesday, August 16, 2016 by himel*

**Physics**

The earth has a radius of 6380 km and turns around once every 24 hours. What is the average speed of a person resting at the equator?

*Tuesday, August 16, 2016 by Jamhie*

**Physics**

the center of gravity of a 100-g stick is located at 50 cm mark and the stick is supported at 60cm. mark, Where must an 80g object be hung in order to have equilibrium?

*Tuesday, August 16, 2016 by Chen*