# physics please HELP !

74,851 results, page 93-
## physics

an object 5cm lenght is placed at distance of 20cm in front of a convex mirror of radius of curvature 30 cm . find the position of the image -
## physics

A 58 kg skier has a speed of 9.5 m/s at point A. She then encounters a 1.75 m deep dip in the snow's surface that has a circular cross section with a radius of curvature of 12 m. -
## Physics

What is the dimesnional formula of length, mass, volume, time, radius, force, frequency of evolution, velocity, gravity, tension -
## physics

Explain the effect increasing temperature has on the following situations and what is happening at the molecular level to cause it. (a) the speed of sound in air (b) the current in a wire THANKS -
## physics

A certain vehicle can accelerate from rest to a speed of 25m/s in a time of 8s.What average power is needed to cause this acceleration?Neglect frictional losses -
## physics

A construction worker is carrying a load of 40 kilograms over his head and is walking at a constant velocity. If he travels a distance of 50 meters, how much work is being done? -
## physics

which of the following properties of a sound wave determines its pitch: wavelength, speed, amplitude, or frequency? Plese show work, Thank you, Silly -
## Physics

A baseball is thrown horizontally off a cliff with a speed of 7.3 ms-1. What is the vertical distance, to the nearest tenth of a meter, that the ball has fallen after 9.4 seconds? -
## physics

If a freely falling rock were equipped with a speedometer, by how much would its speed readings increase with each second IF it were on a planet where g = 20 m/s2? Show all work leading to your answer. -
## Physics

An arrow of mass 1000kg was fired from rest with a velocity of 15m/secs for a period of 0.5secs.calculate the applied force. -
## physics

A ball of mass moves in a horizontal circular path of radius a with speed v as shown in the illustration below. Find the tension in the cord. -
## physics

four resistor of resistances 1ohm,2ohm,3ohm,5ohm, are connected in series and afterwards in parallel.calculate the combined resistance in each case -
## physics

find the effective weight of an astronuat ordinarily weighing 50kg when his rocket moves vertically upwards with 6gm acceleration -
## Physics -- Temp and heat

Your swimming pool is square and 5.7 m on a side. It is 1.5 m deep in the morning. If the temperature changes by 14°C during the afternoon, how much does the depth of the water increase? -
## Physics

Five forces act on an object. (1) 60 N at 90° (2) 40 N at 0° (3) 80 N at 270° (4) 40 N at 180° (5) 50 N at 60° What are the magnitude and direction of a sixth force that would produce equilibrium? Thanks for the help im confused on setting up the f(x) -
## Physics

Electrons are ejected from a photoelectric cell with a maximum kinetic energy of 1.20 eV. If the incident light has a wavelength of 410nm, what is the work funtion? -
## physics

M1 and M2 are two masses connected as shown. The pulley is light (massless) and frictionless. Find the mass M1, given that M2 (7.0 kg) accelerates downwards at 3.39 m/s2, θ is 30o, and μk is 0.45. -
## Physics

Determine the stopping distance for a skier moving down a slope with friction with an initial speed of 20.6m/s. Assume μk=0.178 and θ=5.27. -
## Physics

What is the threshold frequency for the photoelectric effect on lithium (phi= 2.93eV)? What is the stopping potential if the wavelength of the incident light is 400nm? -
## Physics

A bicyclist climbs a hill 17 m tall and then coasts down the other side without pedaling. If the cyclist’s speed was 2.5 m/s at the top, what is it at the bottom (ignoring friction)? -
## physics

Find the magnitude and direction of the net electrostatic force exerted on the point charge q3 in the figure below, where q = +2.5 μC and d = 28 cm. The picture is of a square. q1=+q, q2=-2q, q3=-3q, q4=-4 -
## Physics II

Find the work done in pulling a 120 gram box in an incline plane, 150 cm long and 90 cm high if the coefficient of friction is 0.25. -
## Physics

an airplane travels due north at 500km/hr there's a cross wind of 100km/hr determine the displacement of the air craft after 1 hour -
## physics

What is the required resistance of an immersion heater that will melt 6.39 kg of ice at 0°C in 36 min while operating at 110 V? im not too sure how to do this because delta_T=0. With the equations im using, i get 0 but its not the answer and im not quite -
## Physics

A particle of mass 1.6 x 10-27 kg is revolving on a circular path of radius 10cm under the Influence of a centripetal force of 2.5 x 10-12. Find out the angular velocity? -
## physics

Find the magnitude and direction of the net electrostatic force exerted on the point charge q3 in the figure below, where q = +2.5 μC and d = 28 cm. The picture is of a square. q1=+q, q2=-2q, q3=-3q, q4=-4 -
## Physics

A television tube operates at 20,000V. What is min wavelength for the continuous x-ray spectrum produced when the electrons hit the phosphor? -
## Physics

Starting from rest, Mr.M's bus achieves a velocity of 25 m/s in a distance of 1.0 km. Find the time and the acceleration. I don't know which formula to use. Delta T = Vf - Vi / Aavg ? -
## physics

a body is dropped from the roof of a builindgs 10 m high .calculate the time of fall and the speed with which it hits the ground .take g=10m/second sqare -
## Physics or Science?

Why liquid soap dispensed through a small spout by pressing on it, solidifies interfering with its smooth ejection? thanks so much for an answer! Pietra -
## physics

Suppose you wish to make a solenoid whose self-inductance is 3.0 mH. The inductor is to have a cross-sectional area of 2.0*10^-3 m2 and a length of 0.052 m. How many turns of wire are needed? -
## physics

A bar 5m long has a weight of 50nt attached to the other end is 80nt. Determine the magnitude, direction, and point of application of the equilibriant. -
## Physics

A man pulls a 50 kg box with an acceleration of 2m/s^2 across the floor. He applies a 200 N force at an angle of 30 degrees what is the coefficient of the kinetic friction? -
## Physics

A construction crane's cable lifts a 59.5-kg box upward with an acceleration of 1.38 m/s^2. Find the tension in the rope. 501.585 is incorrect. -
## Physics

Joe stands 150 m from the edge of a canyon wall. How long will it take him to hear his echo if the air temperature is 250 degree C? -
## physics

You are on a hike in the mountains. You have 4.92 km left to go before your next campsite. The sun will set in 6.6 h. What avergae speed must you walk to camp at sunset? Answer in units of km/h -
## physics

for starting from rest and moving in a straight line,runner achieves a velocity of 7m/s in a time of 2 seconds .what is the average acceleration of the runer. -
## Physics

A rocket moves upward, starting from rest with an acceleration of 26.3 m/s2 for 5.43 s. It runs out of fuel at the end of the 5.43 s but does not stop. How high does it rise above the ground? -
## physics

top-fuel drag racers are able to uniformly accelerate at 12.9 m/s from rest 97 m/s before crossing the finish line . How much time elapses during the run ? -
## physics

An 8 hour exposure to a sound level of 95.0 dB may cause hearing damage. What energy in joules falls on a 0.850 cm diameter eardrum so exposed? -
## physics

what is the maximum torque on a rectangular coil 5 cm x 12 cm and with 600 turns when carrying a current of 0.0700A in a uniform field with magnitude 0.300T? -
## physics 2

calculate the mass of air inside a 500 liter container at a pressure of 200 kpaa and temperature is 30 degree celsuis -
## physics

the sound from a mosquito is produced when its wings vibrates at an average rate of 500 vibrations/sec.What is the tine period of the vibration? -
## physics

Evaluate the following statement (T/F/N), explain: If you reduce by half the distance between two point charges, you double the magnitude of electrical force that each exerts on the other. -
## Physics

During a football game, A is 8.0 m behind B and is running at 7.0 m/s when B catches the ball and starts to accelerate away at 2.8 m/s(squared) from rest. a) Will A catch B? If so, after how long? b) How far down the field will B have run? -
## Physics

An oscillator with a mass of 520 g and a period of1.2 s has an amplitude that decreases by 2.20% during each complete oscillation. At what time will the energy be reduced to 15.0% of its initial value? -
## physics

A young boy swings a yo-yo horizontally above his head so that the yo-yo has a cen- tripetal acceleration of 240 m/s2. If the yo-yo’s string is 0.29 m long, what is the yo-yo’s tangential speed -
## physics (urgent)

A flywheel with a moment of inertia of 1.00kg m^2 is rotating at 100 rpm. What torque is required to bring it to rest in 10.0 revolutions? -
## physics

a car whose brakes are locked skids to a stop in 100m from an initial velocity of 20m/s. find the coefficient of sliding friction -
## physics

The steel I-beam in the drawing has a weight of 7.10 kN and is being lifted at a constant velocity. What is the tension in each cable attached to its ends? (Assume α = 70.8°.) -
## Physics

PLEASE HELP! and include steps of how you solved it! What magnitude of force, acting for 0.025 s, will change the velocity of a 100 g ball from 30 m/s eastward to 40 m/s westward? -
## physics

What net force would actually be necessary to stop an automobile of mass 880 traveling initially at a speed of 52.0 in a distance equal to the diameter of a dime, which is 1.8 ? -
## physics

An 8 hour exposure to a sound level of 95.0 dB may cause hearing damage. What energy in joules falls on a 0.850 cm diameter eardrum so exposed? -
## physics

An 8 hour exposure to a sound level of 95.0 dB may cause hearing damage. What energy in joules falls on a 0.850 cm diameter eardrum so exposed? -
## physics

A stone is thrown downward into a well with an initial speed of 5.00 m/s. The sound of splash is heard 1.50 s later. Find the depth of the well if the air temperature is 15.0 ˚C? -
## physics

a stone is projected vertically upward and reaches a maximum height of 20m before it returns to the thrower find the total time taken -
## Physics

An outfielder throws a 0.150 kg baseball at a speed of 26.0 m/s and an initial angle of 30.0°. What is the kinetic energy of the ball at the highest point of its motion? -
## physics

A body of mass 300g movers in a circle of 4m at a uniform speed of 12m/s. Calculate the angular velocity and the tripetal force -
## physics

how many electrons must be removed from each of the two 5kg copper spheres to make the electric force of repulsion between them equal in magnitude to the gravitational attraction between them? -
## physics

A rotating uniform cylindrical platform of mass 240 kg and radius 5.7 m slows down from 3.9 rev/s to rest in 16 s when the driving motor is disconnected. -
## Physics

A proton and an electron have the same kinetic energy upon entering a region of constant magnetic field. What is the ratio of the radii of their circular path? -
## physics

Find the horizontal distance the skier travels before coming to rest if the incline also has a coefficient of kinetic friction equal to 0.228 -
## Physics

What is the magnitude of the apparent weight of a 65 astronaut 3600 from the center of the Earth's Moon in a space vehicle moving at constant velocity? -
## physics

a gymnast tumbles forward 4.0m does cartwheels to the left for 6.0 m and climb a vertical rope to a height of 3.0m. What is the magnitude of the plane's displacement from the airport? -
## general physics

What is the smallest number of whole logs (ñ = 725 kg/m3, radius = 0.0556 m, length = 3.80 m) that can be used to build a raft that will carry four people, each of whom has a mass of 73.0 kg? -
## physics

A window air conditioner consumes 900 W of electric power and has COP = 2.9.If it runs continuously for 24 h , how much heat gets removed from the house? -
## Physics

A proton and an electron have the same kinetic energy upon entering a region of constant magnetic field. What is the ratio of the radii of their circular path? -
## physics homework

0.2kg mass hangs at the end of the wire. what is the tension if the ball is then whirled around in a horizontal circle with tangential velocity of 5m/s -
## math,physics,chemisty,biology

the number of moles of H2O2 required to completely react with 400ml of 0.5N KMnO4 in acidic medium are -
## Physics

A 69 kg skier speeds down a trail, as shown in the figure. The surface is smooth and inclined at an angle of θ = 17° with the horizontal. Help me with an equation to solve. thanks! -
## physics

A roller coaster car is moving at 20.0m/s along a straight horizontal track. what is the speed after climbing a 15.0m hill? neglect the effects of friction -
## physics (fluids)

If a object of radius 3 cm is attached to the ground in a 3 m deep sea, what is the vertical force in N with which the water (density = 1000 kg/m^3) presses on it? -
## Physics

A girl weighing 310 N sits on a hammock supprted by two ropes. Each tied 60 degree from vertical posts. What is the tension on each rope? -
## Physics 1

What is the minimum speed a 3,200 pound car can have on a flat road when going around a curve with a radius of 300ft. Take the static coefficient of friction to be 0.8. -
## Physics

Find The Potential Energy Of A Boy Mass 10kg Standing On A Building Floor Of 10 Metres Above Ground Level. 10*10*10 =1000 -
## physics help

A 1000-kg car moving at 10 m/s brakes to a stop in 5 s. The average braking force is? when i work this out with the formula that you gave me, i get 2525 instead of 2000 N -
## Physics

A roller-coaster car is moving at 20.0 m/s along a straight horizontal track. What is its speed after climbing a 15.0 m hill? Neglect the effects of friction. -
## Physics

Calculate the tension in the string if a single pulley of velocity ratio 5 is used to raise a body of mass 200g through a distance of 4cm. -
## physics

A production line inspector wants a mirror that produces an image that is upright with a magnification of 7.1 when it is located 10.0 mm from a machine part. What is its radius of curvature? -
## physics

Determine the frequency and period for a pendulum of length 250cm, mass of 500g, and amplitude of 25cm I don't understand how to do this, help would be appreciated! Thank you -
## Physics

Need help with a question! I worked out A (assuming its right) which leads to B. A) C=1.03x10^-4 uF, A=2.5mm^2, d=0.75um B) If the voltage across the membrane is delta V= 75mV, what is the charge +_Q on each surface A? thanks! -
## physics

A Martian rover is moving up a hill sloped at 30.0° with the horizontal. If it has a constant velocity of 1.50 meters/second, calculate its vertical displacement after 21.0 seconds -
## physics

An automobile manufacturer claims that its product will travel 1.2 km in 27 s, starting from rest. What is the magnitude of the constant ac- celeration required to do this? Answer in units of m/s2. -
## Physics

Calculate the magnetic flux density in air at a point 15mm from a long straight wire carrying a current of 100A -
## physics

With an average acceleration of −1.6 m/s^2, how long will it take a cyclist to bring a bicycle with an initial speed of 13.3 m/s to a complete stop? Answer in units of s -
## physics

An old-fashioned single-play vinyl record rotates on a turntable at 46.0 rpm. What are (a) the angular velocity in rad/s and (b) the period of the motion? -
## physics

As a young boy swings a yo-yo parallel to the ground and above his head, the yo-yo has a centripetal acceleration of 250m/s^2. If the yo-yo's string is 0.50 m long, what is the yo-yo's tangential speed? -
## Physics

A bullet fired into a fixed target loses half of its initial velocity in penetrating 15cm. How much further it will penetrate before coming to rest? -
## Physics

A 21.0 kg child descends a slide 3.4 m high and reaches the bottom with a speed of 2.0 m/s. How much thermal energy due to friction was generated in this process? -
## physics

You are on a hike in the mountains. You have 3.03 km left to go before your next campsite. The sun will set in 5.2 h. What average speed must you walk to get to camp at sunset? Answer in units of km/h. -
## Physics

If a Saturn V rocket with an Apollo spacecraft attached has a combined mass of 2.6 105 kg and reached a speed of 11.2 km/s, how much kinetic energy would it then have? _____J -
## physics

a stone propelled from a catapult with a speed of 50ms-1 attains a height of 100m. Calculate the time of flight and the angle of projection -
## Physics

An object of mass 10kg is placed on an inclined plane at 30 degree to the horizontal. Calculate the reaction between two surface and what is the coefficient of static friction. -
## Physics

Circular motion: Not sure if I did this right. I need to find the speed that a spaceship needs to rotate to create an artificial gravity of 9.8m/s^2 (at feet) r=10m a=V^2/r 9.8=v^2/r root of(9.8*10)=v v=9.9m/s is this close? -
## physics

The Sun radiates about 4 × 1026 J of energy into space each second. How much mass is released as radiation each second? The speed of light is 3 × 108 m/s. Answer in units of kg -
## Physics

What is the greatest safe speed, without skidding, that a 1700 kg car can have on a level curve of radius 215 meters if Mk=0.4 and Ms=.85? Answer=42.3 I tried using the equation mv^2/r=mg+Mk. -
## Physics

A rocket initially at rest accelerates at a rate of 80 m/s^2 for 0.74 min. What is its speed at the end of this time? Answer in units of m/s. Plz help and explain -
## physics

If a Saturn V rocket with an Apollo spacecraft attached has a combined mass of 2.6 105 kg and reached a speed of 11.2 km/s, how much kinetic energy would it then have? __________J -
## Physics

1a. Two converging lenses, each of focal length 14.4 cm, are placed 60.6 cm apart, and an object is placed 26.9 cm in front of the first. Where is the final image relative to the second lens formed? b. What is the magnification of the system? -
## physics

A typical color television draws about 2.8 A when connected to a 145 V source. What is the effective resistance of the T.V. set? Answer in units of Ω.