# Physics!

73,661 results, page 87

### Physics

Find the average velocity of a projetile between the instants it crosses half the maximum heght.It is projected with a speed u at an angle ø(thita) with horizontal.

### PHYSICS (conceptual doubt)

If a professional jumper jumps in a running train and remains in air (say for ~5 sec),does he return back to his orginal position?

### Physics

If a bullet is fired with the speed of 6.0x10² m/s horizontally from a height of 48 m, how long will it take to hit the ground? What is The range of projectile? Assume that there is no air resistance.

### physics

The graphs below show position as a function of time for three different objects. Describe the similarities and differences of these motions. Explain your answer.

### physics

Use the fact that the speed of light in a vacuum is about 3.00 108 m/s to determine how many kilometers a pulse from a laser beam travels in exactly 4.9 hour(s)

### physics

Use the fact that the speed of light in a vacuum is about 3.00 108 m/s to determine how many kilometers a pulse from a laser beam travels in exactly 4.9 hour(s)

### physics

A football is thrown upward at a(n) 37 angle to the horizontal. The acceleration of gravity is 9.8 m/s2 . To throw a(n) 57.8 m pass, what must be the initial speed of the ball? Answer in units of m/s

### physics

during takeoff, an air plane goes from 0 to 360km/hr in 5s. A.) what is its acceleration? B.) How fast is it going after 5 s? C.) How far has it traveled by the time it reaches 50m/s?

### physics

If a ball is thrown vertically upward with initial velocity of 8 meters per second, what would the speed be when it returns to the starting point with acceleration of 9.81?

### physics

It two objects are thrown off a tall building and one is three times the mass of the other, do they hit the ground at the same time?

### Physics!

Suppose that you are standing on a train accelerating at 0.39g. What minimum coefficient of static friction must exist between your feet and the floor if you are not to slide?

### Physics

A 0.55 kg block slides across a tabletop with initial velocity of 3 m/s and it comes to rest in a distance of 0.53 m. Find the average friction force that retarded its motion.

### college physics

How many revolutions per minute would a 18 m-diameter Ferris wheel need to make for the passengers to feel "weightless" at the topmost point?

### physics

A ball is thrown vertically upward with a speed of 27.3 m/s from a height of 2.1 m. How long does it take to reach its highest point? The acceleration of gravity is 9.81 m/s2. Answer in units of s

### physics

a worker pushing a wheelbarrow of mass 50 kg with a constant velocity along a horizontal surface whose coefficient of friction is 0.5 and the angle of force is 30 degree

### physics

A person with a mass of 77.5 kilograms is pushed on a sled across the frictionless surface of a frozen pond with a constant horizontal force of 14.8 Newtons. What is their acceleration?

### College Physics

Find the minimum work required to carry a truckload of furniture weighing 1.99 104 N to a third-story apartment, 24.0 m above the truck.

### physics

A ball is thrown upward.What is its maximum height? Its initial vertical speed is 11.5 m/s and the acceleration of gravity is 9.8 m/s2 . Neglect air resistance. Answer in units of m

### physics

During a baseball game, a batter hits a pop- up to a fielder 78 m away. The acceleration of gravity is 9.8 m/s2 . If the ball remains in the air for 5.8 s, how high does it rise?

### physics

A long jumper leaves the ground at an angle of 22.1◦ to the horizontal and at a speed of 10 m/s. How far does he jump? The acceleration due to gravity is 9.8 m/s2 . Answer in units of m

### Physics Honors

The same rock is thrown upwards at an angle of 45 degrees. It travels 10 meters up to its maximum height. How far will it travel before it lands?

### physics

In a roller coaster ride cars and passengers slide down an incline of 36 degrees to horizontal if the friction is negligible find magnitude of acceleration

### physics

an experimental jetplane just after takeoff climbs with a speed of 500km/hr at an angle of 37 degrees with the horizontal. At what rate is the plane gaining altitude?

### physics

Find the minimum diameter of a 51.5-m-long nylon string that will stretch no more than 1.01 cm when a load of 68.9 kg is suspended from its lower end. Assume that Ynylon = 3.51·108 N/m2.

### physics

Find the minimum diameter of a 51.5-m-long nylon string that will stretch no more than 1.01 cm when a load of 68.9 kg is suspended from its lower end. Assume that Ynylon = 3.51·108 N/m2.

### physics

A beautiful man with a large nose named Melvin lifts a 28.1 kg bucket from a well anddoes 4.24 kJ of work. The acceleration of gravity is 9.8 m/s2 . How deep is the well? Answer in units of m

### physics

How fast a Ford Focus car weighing 1200 kg should be moving to have the same momentum as the bullet? Express your answer in miles/hr.

### physics

Two comets, each of mass 6500 kg and traveling 88 m/s in opposite directions, collide head-on and come to rest. How much energy is produced in this collision?

### physics

Find the minimum diameter of a 51.5-m-long nylon string that will stretch no more than 1.01 cm when a load of 68.9 kg is suspended from its lower end. Assume that Ynylon = 3.51·108 N/m2

### Physics

Radio waves travel at the speed of light, which is 3.00 108 m/s. What is the wavelength for a FM station broadcasting at 105.9 MHz (the prefix M is "mega" and means 106)?

### physics

Assuming maximal power output, how long, in seconds, would it take a 1,535 kg car with a 128 hp engine to accelerate from 50 km/h to 102 km/h? (1 hp = 746 W)

### physics

If a man has an average useful power output of 31 W, what is the minimum time, in s, it would take him to lift fifty 12.3 kg boxes a height of 2.3 m. i'm not sure how to go about it if anyone can help me Thanks

### physics

If a man has an average useful power output of 31 W, what is the minimum time, in s, it would take him to lift fifty 12.3 kg boxes a height of 2.3 m. i'm not sure how to go about it if anyone can help me Thanks

### physics

an object of mass 150kg is pulled on a horizontal rough ground by a force of 900newton(N).find the coefficient of static friction (taken g=10m/s)

### Help- Physics

How much work did the movers do (horizontally) pushing a 130kg crate 10.1 m across a rough floor without acceleration, if the effective coefficient of friction was 0.50?

### Physics

A 1.5 N force acts on a .20 kg cart so as to accelerate it along a frictionless track. If it is accelerated from rest, how fast is it going after .3m? The answer given is 2.12 m/s but I am not sure how to get to that.

### 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) and f(y)

### Physics

If Galileo and his assistant were 16 km apart, how long would it take light to make the round-trip? How does this time compare with reaction times of about 0.4 s?

### physics

a ball of mass 0.4 kg is initially at rest on the ground. It is kicked and leaves the kicker's foot with a speed of 5 m/s in a direction of 60 degrees above the horizontal. What is the impulse

### Physics

What is the maximum acceleration of a platform that oscillates with an amplitude of 2.1 cm at a frequency of 6.7 Hz? I feel like this is a very simple question, but I'm having trouble figuring it out.

### physics

The velocity of a diver just before hitting the water is -11.1 m/s, where the minus sign indicates that her motion is directly downward. What is her displacement during the last 1.18 s of the dive?

### physics

The earth's atmosphere extends to a height of nearby 200KM above its surface there many be explosion and noises taking place in the outer space but we do not hear them.why?

### URGENT! PHYSICS

HI! I searched on a lot of websites for this, but none of them actually was right for me. I need to do an egg drop withh only straws and glue/tape. Thanks!

### physics

A drag racer starts her car from rest and accelerates at 9.0 m/s2for the entire distance of 105.0 m. What is its speed at the end of the run? Answer in units of m/s.

### physics

A person wearing a safety belt can withstand an acceleration of -3.0E2 m/s2. How thick should barriers be to safely stop a car that hits a barrier at 97 km/h?

### Engineering/physics

Calculate the moment if you were to hold a 15lb bowling ball with your arm straight out and your forearm perpendicular to your body. What is the pinnned connection

### physics

a rock climber weights 550N and is carrying a backpack that weighs 50N. how much total work has been done after she climbs 12m

### physics

using a sketchs, show the type of directions of forces acting on the following farm hand tools i) a hoe ii) a rake for land clearing 0

### Physics

A force of 250 N is just sufficient to start a 50 kg steel trunk moving across a wooden floor. Find the coefficient of static friction.

### Physics

The heat of fusion of water is 80 cal/g. When 25 g of ice at 0ºC is placed in the contents of a 12 oz can of Coke (≈350 g) at 25ºC, what is the final temperature of the beverage?

### physics

A ball is dropped from a high building. Using the approximate value of g = 10 m/s2, find the change in velocity between the fourth and seventh second of its flight

### physics

How deep can a snorkel diver dive if the maximum gauge pressure on the thorax cannot exceed 10.9 kPa? Hint: density of seawater = 1.015g/cm3

### physics

Two equals negatives charges (-1.75x10^(-19) Coulb) are separated by an insulator at a distance of 0.230 mm. Find the electrostatic force between these electrons?

### 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

Two forces are applied to a car in an effort to move it, as shown in the following figure, where F1 = 416 N and F2 = 363 N. (Assume up and to the right as positive directions.)

### physics

If the coefficient of kinetic friction between tires and dry pavement is 0.800, what is the shortest distance in which an automobile can be stopped by locking the brakes when traveling at 25.7 ?

### physics

If the height of the water slide in the figure below is h1 = 1.55 m and h2 = 1.35 m, and the person's initial speed at point A is 0.593 m/s, at what location does the swimmer splash down in the pool?

### Physics

Use the first law of thermodynamics to determine the amount of heat change, Q, and whther it was added to or removd from the system. W=225J Delta U=600J Q=?

### Physics

You throw a baseball straight up at 40 m/s and it reaches its peak after 4.00 seconds. What is its speed when it falls back into your hand? What is its displacement? What distance has it traveled?

### physics

According to newtons 1st law , construction workers are warned not to leave their hard hats on the rear window ledge of their cars, explain why?

### physics

Qualitatively explain how you would expect the kinetic energy to change as a glider slides down an inclined air track, where friction is negligible.

### physics

Qualitatively explain how you would expect the potential energy to change as a glider slides down an inclined air track, where friction is negligible.

### physics

If the coefficient of kinetic friction is 0.25 , how much horizontal force is needed to pull each of the following masses along a rough desk at a constant speed? A) 25 kg

### Physics

A triply ionized beryllium atom (Be3+) has only one electron in orbit about the nucleus. What is the radius of the ion when it is in the n = 9 excited state?

### physics

two perfect elastic balls of same mass m are moving with velocities u1 and u2 . they collide elastically n times. the kinetic energy of the system finally is?

### physics

determine the static coefficient of friction if a box will be rasied at rest, right up until the point that the board on which it is sitting gets raised to 53 degrees.

### physics

a circular wire loop of radius 5cm lies in the xy-plane in a magnetic field defined by B=-(4t^2+3t).determine the voltage across the resistor at time t=2s

### Physics

A 52kg ice hockey player moving at 11m/s slows down and stops over a displacement os 8.0m. Calculate the net force of the skater.

### Physics Help please

A bus moving with speed 0.93c is 65 feet long according to its passengers and driver. What is its length from your vantage point on a fixed planet?

### PHYSICS Help please!!

The two-mile linear accelerator at Stanford University in California "appears" to be less than a meter long to the electrons that travel in it. Explain.

### physics

two objects of masses m1 and m2 fall freely from height h1 and h2 in a vertical plane respectively.The ratio of time taken by them is how much by reaching the ground?

### physics help please

question # 1 :Estimate the work you do to mow a lawn 13m by 23m with a 60cm wide mower. Assume you push with a force of about 15 N

### Physics

The minimum frequency for the photoelectric effect of a zinc plate is 9.7 × 1014 Hz. What will be the kinetic energy of an ejected electron when a photon with a wavelength 200 nm (2.00 × 10 7 m) strikes it?

### Physics

A 6.25 kg solid ball with a radius of 0.185 m rolls without slipping at 3.55 m/s. What is its total kinetic energy? I didn't understand what the last person gave me for help can someone please help me!

### Physics

An airplane flying at 82km/hr at 30 degrees east of north encounters a 40km/hr wind due west. What is the speed of the plane relative to the ground?

### Physics

An object slides down a frictionless 33 degree incline whose vertical height is 54.0 cm. How fast is it going in meters/second when it reaches the bottom?

### physics

A baseball is thrown horizontally off a cliff with a speed of 11 ms^-1. What is the vertical distance, to the nearest tenth of a meter, that the ball has fallen after 4.8 seconds?

### physics

A spherical baloon expands when it is taken from the cold outdors to the inside of a warm house. if its suface area increases 16%, by what percentage does the radius change

### physics

The highest George can suck water up a very long straw is 2.0m What is the lowest pressure he can maintain in his mouth? Express to two sig figs

### physics

What is the magnitude of the electrostatic force that the two protons inside the nucleus of a helium atom exert on each other? Why do atomic nuclei not simply explode?

### physics

a ball is thrown upward what is its maximun height? its initial vertical speed is 8.1 m/s and the acceleration of gravity is 9.8 m/s . neglet air resistance . answer in units of m

### physics

a car travelled 1/3 of the way between two citties with speed of 80 km/hr, then continues moving with 130 km/hr. find his average velocity for the whole trip

### physics

A diver jumps off a diving board with a speed of 25m/s he returns to the water after 3s. At the top of his dive describe his velocity and his acceleration?

### physics

determine the acceleration for a jet taking off on a run way as it starts from rest and reaches a velocity of 50m/s over a period of 10s

### Physics

On some planet other than Earth a ball is thrown upward at a velocity of 22.3 m/s. It returns back to the exact position that it started at in 8.8s. What is this planets value for "g"? (

### Physics

a 150-N and 80-N force act upon an object. the angle between the two forces is 55 degrees. determine the magnitude and direction by trigonometric calculations.

### physics

You drive a car 2.0 km to the gas station, 4.0 km to the shopping mall to let your mother off, and 4.5 km back home. The trip takes 20.0 min. What is your average speed?

### physics

In a new scenario, the block only makes it (exactly) halfway through the rough spot. How far was the spring compressed from its unstretched length?

### PHYSICS

(a) how long it took King Kong to fall straight down from the top of a 210 m high building s (b) his velocity just before "landing"

### physics

A ball is thrown vertically upward with a speed of 24.7 m/s from a height of 2.0 m. How long does it take to reach its highest point? The acceleration of gravity is 9.81 m/s 2 . Answer in units of s

### physics

A ball is thrown vertically upward with a speed of 24.7 m/s from a height of 2.0 m. How long does it take to reach its highest point? The acceleration of gravity is 9.81 m/s 2 . Answer in units of s

### physics

A rocket moves upward, starting from rest with an acceleration of 32.0 m/s2 for 3.27 s. It runs out of fuel at the end of the 3.27 s but does not stop. How high does it rise above the ground?

### science[physics]

three masses 3kg,4kg,5kg are located at corners of an equilateral triangle of side 1m.locate the centre of mass of the system

### Physics

1. 125g mass attached to a string oscillates with an amplitude of 7.8cm and a maximum speed of .625 m/s. Find (a) the force constant and (b) the period of motion.

### physics

For a given velocity of projection in a projectile motion, the maximum horizontal distance is possible only at ө = 45°. Substantiate your answer with mathematical support. 20.5 m/s

### Physics

A heavy freight train has a mass of 13200 metric tons. If the locomotive can pull with a force of 755000N, how long does it take to increase it's speed from 0 to 95.5 km/h?

### Physics

The coefficient of kinetic friction for a 34.3 kg bobsleigh on a track is 0.150. What external force is required to push it down a 5.60° incline and achieve a speed of 60.12 km/h at the end of 75.2m ?

### physics

A 0.5 kg block is sliding along a table top with an initial velocity of 0.2 m/s. It slides to rest in a distance of 70 cm. Find the frictional force that is slowing its motion.

### Physics

Suppose the surface (radius = r) of the space station in the figure is rotating at 38.6 m/s. What must be the value of r for the astronauts to weigh one-half of their earth-weight?