# Math/Physics

208,897 results, page 79

### physics

WHAT IS THE REASON BEHIND THE JISKHA"S TEACHERS TO BE NOTHING!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!(except Writeacher and STEVE) ARE THEY DAFT OR NUISANCE!!!!!!!!!!!!!!!!!! ANSWWER Me QUICKLY !!!!!!!!!!!!!

### Physics

A 45 kg child sits on a 5 kg sled and slides down a 117 meter, 31 degree slope, to the nearest m/s what is his or her speed at the bottom?

### Physics

A 45 kg child sits on a 5 kg sled and slides down a 117 meter, 31 degree slope, to the nearest m/s what is his or her speed at the bottom?

### College Physics

How much would you have to raise the temperature of a copper wire (originally at 20 ∘ C) to increase its resistance by 30% ?

### Physics

A pendulum has a mass of 3.2 kg, a length of 2 meters and swings through a (half)arc of 28.1 degrees. What is its amplitude to the nearest centimeter?

### physics

the substance which allows heat radiations to pass through is.a)iron b)water vapour c)wood d)dry air

### physics

Two blocks of masses m and 2m are held in equilibrium on a frictionless incline as in the figure. In terms of m and θ, find the following.

### Physics

How much time would Simpson save by in- creasing his average velocity to 65.8 km/h to the east? Answer in units of min

### Physics

A car accelerates uniformly from rest to a speed of 23.9 km/h in 8.2 s. Find the distance it travels during this time. Answer in units of m

### Physics

A 92 kg disk, with a radius of 0.97 meters, is rotating at 562 rpm. What is its angular momentum, to the nearest tenth of a Joule*sec?

### Physics

a rubber ball is thrown downwards off a balcony. after it travels 55m it has a speed of 46.5m/s. what is the initial velocity

### physics

A football is thrown upward at a 30 degree angle to the horizontal. To throw a 40.0-m pass, what must be the initial speed of the ball?

### Physics

Find the magnitude and direction of the equilibrant force for these two concurrent forces: 13.5 N, E and 32.0 N, N. Pls HELP me answer this. Thank u very much.

### college physics

Show that 480W of power is expended by a weightlifter when lifting a 60-kg barbell a vertical distance of 1.2m in a time interval of 1.5s.

### physics

You are driving north on a highway. Then, without changing speed, you round a curve and drive east. Does your velocity change

### Physics

A 0.5 kg air-hockey puck is initially at rest. What will its kinetic energy be after a net force of 0.8 N acts on it for a distance of 0.5 m?

### Physics

an object is pushed horizontally by a 0.0840-kiloN force over a frictionless table. find the resulting acceleration

### physics

What net torque is required to give a uniform 12-kg solid ball with a radius of 0.22m an angular acceleration of 12rad/s2 ?

### physics

The difference in energy between allowed oscillator states in HBr molecules is 0.330 eV. What is the oscillation frequency of this molecule?

### Physics

A regulation baseball has mass 145 g and diameter 22.86 cm. Will this ball float or sink in water? Vsphere = € 4 3π⋅r3

### Physics

A regulation baseball has mass 145 g and diameter 22.86 cm. Will this ball float or sink in water? Vsphere = € 4 3π⋅r3

### physics

A boy jumps at a speed of 16.0 m/s at an angle of 20.0 above the horizontal. How long does he stay in the air before touching the ground? A. 1.53 s B. 1.12 s C. 3.07 s D. 4.2 s

### Physics-science

what is the heat required in kilo calories to covert 2kg of ice at 0 c completely into stream at 100c

### physics

A boy of mass 50kg runs up a set of stairs of total height of 3.0m.find the work done against gravity

### physics

a block with a velocity 4m/s slides 8m across a rough horizontal floor before coming to rest.the coefficient of friction is.

### physics

A 101.6-N bird feeder is supported by three cables as shown in the figure below. Find the tension in each cable

### Physics

Two protons, an infinite distance apart are brought together to a separation of 1 nm. What is the initial potential energy of the system?

### Physics

A certain radioactive element has a half liv of 20days, how long does it take 3/2 of the atom originally present to disintegrate

### Physics 141

A car is on a circular track of radius r = 100 m. It's tangential speed is 30 m/s. How many lateral gravities does the driver feel?

### physics

A 2.284 km car is moving down a road with a slope of 13% at a constant speed of 11 m/s. What is the direction and magnitude of the frictional force?

### Physics

A racing car has a mass of 1530 kg. The acceleration of gravity is 9.8 m/s^2. What is its kinetic energy if it has a speed of 136 km/h? Answer in units of J.

### Physics

Prove that tanø is equal to U(k) when the block slides down the incline with a constant speed. (Use symbols, not numbers.)

### physics

What force should the woman in Figure 9.45 exert on the floor with each hand to do a push-up? Assume that she moves up at a constant speed.

### PHYSICS

A grinding wheel 0.3m in diametre has amass of 5kg is rotating at an angular velocity of 2300rev/min.what is the kinetic energy?

### PHYSICS

A grinding wheel 0.3m in diametre has amass of 5kg is rotating at an angular velocity of 2300rev/min.what is the kinetic energy?

### Physics

When a compact disk with a 12.0-cm diameter is rotating at 4.2 rad/s, what is (a) the linear speed and (b) the centripetal acceleration of a point on its outer rim?

### Physics

If the heat of 110J is added to a gaseous system, change in internal energy is 40J, then the amount of external work done is?

### Physics

A magnifying glass (a positive lens) with a focal length of +6 cm is placed 2 cm above a page of print. What is the magnification of this image?

### physics

A shout down a well produces an echo in 2.00 seconds. How deep is the surface of the water in the well? Assume the speed of sound to be 343 m/s.

### Physics

If it takes a particle in SHM 0.60ss to travel from the equilibrium position to the maximum displacement (amplitude), what is the period of oscillation?

### physics

what is the magnitude and the direction of an electric field when an electron is accelrated vertically upward at a distance of 5.5 metres in 3 micro seconds?

### physics

Why does the pitch of the sound produce by blowing over an open end of a bottle change when you have more water in it?

### physics

Determine the launch speed of a horizontally-launched projectile which lands 27.4 meters from the base of a 17.9-meter high cliff.

### physics

if a train travell at speed of 90km/hour. and when the break applied at 5m/sec2. how much it will travel before stoping

### physics

What is the frequency of the second hand of a clock, assuming it is keeping correct time? Select one: a. 1 Hz b. π/3 Hz c. 0.0167 Hz d. 60 Hz

### Physics

After undergoing through 90 degree compton scattering, the fraction of energy lost by photon is A) 10 % B) 50 % C) 20 % D) Zero E) None

### Physics

an 80kg man jumps off a 60m cliff, halfway to the ground, his GPE is 27,072J. What is his KE at the same moment?

### physics

A skateboarder, with an initial speed of 4.2m/s , rolls virtually friction free down a straight incline of length 16m in 3.3 s.

### physics

a 150 metre long train crosses a bridge of length 250 metres in 25 seconds find its velocity

### Physics

A man was lost in the woods. He wanders 3 km north, then 7 km east, then 7 km south, then 4 km west. What is the magnitude and direction of his resultant displacement?

### PHYSICS

IF EARTH WERE TO ROTATE FASTER THAN ITS PRESENT SPEED THEN WEIGHT PF OBJECT WILL DECREASE AT EQUATOR BUT REMAIN UNCHANGED AT POLES why?

### physics

a box of treasure with a mass of 92 kg and volume of 0.031metrecubic lies at the bottom of the ocean.how much force is needed to lift it?

### physics

A sound registers 77.9 decibels on a detector. What is the intensity in W/m2? Assume the threshold of human hearing is 1.0×10-12 W/m2. Give your answer in picowatts/m2. 1 pW = 1×10-12 W/m2

### Physics

Calculate the height through which a crane can lift a load of 4t , when its motor of 4HP operates for 10s. [Take g=10N/kg ]

### physics

show a car that travels 5 km due east and makes a u-turn to travel another 3 km find distance covered and its displacement

### physics

from point A, a boy walks 4 m to the east,2 m to the sout, 4 m to the west , and finally, 2 m to the north , find the distance he travelled and his displacement

### physics

An airplane travels 200 km/h through the air. If it heads directly against a 40- km/h wind, what is its speed relative to the ground?

### Physics

What is the average braking force required of a 1200kg car in order for it to come to rest from 60km/h in a distance of 25m

### AP Physics

If you are driving 116 km/h along a straight road and you look to the side for 1.0 s, how far do you travel during this inattentive period?

### physics

The edges of a shoebox are measured to be 11.9 cm, 17.3 cm, and 29 cm. Determine the volume of the box retaining the proper number of significant figures in your answer.

### physics

In our country and in most of other countries ,the Celsius scale is more commonly used . Can you think of a reason for this?

### physics

Calculate the acceleration of a ball that starts from rest, rolls down a ramp, and gains a speed of 24m/sm/s in 5.8 seconds.

### physics

If a pull of 350 N accelerates a 38-kg child on ice skates at a rate of 7.3 \frac{m}{s^2}, what is the frictional force acting on the skate?

### Physics

Force acting on conductor when placed in magnetic field from east to west horizontal component is 3.0 and current is 10A

### physics

A chunk of Martian rock falls off of a cliff and drops 47.7 m in 5.00 s. What is the acceleration due to gravity on the surface of Mars?

### physics-intro

How much work is done in lifting 450 lb of cement 75 ft above the ground? So basically its W=fs (450lb)(75ft)=33750lb

### physics

A grenade thrown straight up in the air has an initial speed of 27 m/s. How long will it take before it returns to the thrower's hand?

### physics please help

Forces of 4.57 N and 4.74 N act at right angles on a reddish-green block of mass 5.76 kg. How much acceleration occurs?

### physics

distance a cannonball travels when shot horizontally with a velocity of 28.3 at 30 degrees? I'm not sure what formula I need to use. Please help.

### Physics

The power output of an elevator is 15000 W. How many persons could it carry if it raises passenger to a height of 35 m in 20 s ( each person has an average mass of 60 kg)?

### Colle physics

For an object in uniform circular motion, on what parameters does the experimental determination of the centripetal force depend when using F = ma

### physics

A ball initially at rest rolls down a hill with an acceleration of 4.5 m/s2. If it accelerates for 7.9 s, how far will it move? Answer in units of m

### physics

A kettle brings water to boil by using 233 C of charge over the course of 1.25 minutes. The amount of current that was used is _.__ A?

### physics

Please Help!! How much power is developed by a jumbo jet that cruises at 250 m/s. When the trust of its engine is 100,000 N? Thanks!!!

### Physics

You throw a ball towards a wall at 15ms-1, and it bounces back at 10ms-1. What is the total change in velocity? (the answer is not 5m/s)

### physics

A 600 kg car is moving on a level road at 30 m/s. How large of a braking force is needed to stop it in a distance of 75m?

### physics

If you use a horizontal force of 30.0 N to slide a 12.0 kg wooden crate across a floor at a constant velocity, calculate the acceleration.

### physics

The movement of an object or a point mass at a constant speed around a circle that has a fixed radius is called uniform

### 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?

### 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?

### physics

A racing car has a mass of 1970 kg. The acceleration of gravity is 9.8 m/s^2. What is its kinetic energy if it has a speed of 102 km/h? Answer in units of J.

### Physics

An outfielder throws a baseball to home plate with a velocity of +15 m/s and an angle of 30°. When will the ball reach its highest altitude? (Points : 3) 1.2 s 1.5 s 0.77 s 0.50 s

### physics

A 30.0 kg block falls from a height of 30,4 m. assuming a closed system its speed just before hitting the ground is about?

### Physics

At highway speeds, a particular automobile is capable of an acceleration of about 1.52 m/s2. At this rate, how long does it take to accelerate from 74.0 km/h to 104.0 km/h? (in s)

### physics

a stone propelled from a catapult with a speed of 50mls,attains a height of 100m. Calculate the angle of projection and range.

### Physics

What is the gravitational force between two 10 kg iron balls separated by a distance of 0.1 m? How does this compare with the weight of one ball?

### physics

A 4.3kg object moves across a floor with a velocity of + 8.2 m/s and slides to rest in 5.8 s. The net force producing this acceleration is:

### physics

What potential difference is needed to stop an electron having an initial speed of 3.70x 105 m/s? Answer in volts

### Physics

A 6.5-kg bowling ball thrown with a speed of 5.4 m/s hits a stationary 1.75-kg pin. What is the velocity of each object? Assume that the coefficient of restitution is 0.75.

### Integrated Physics and Chemistry

What are a few of the positive things the Equal Rights Amendment would have done for women in America?

### Physics

A racing car has a mass of 1770 kg. The acceleration of gravity is 9.8 m/s2 . What is its kinetic energy if it has a speed of 133 km/h? Answer in units

### physics

A force of 34.5 meganewtons of thrust launches a Saturn 5 rocket 393 km off the ground. How much work was done (in joules)?

### physics

a uniform plank of lenght 5m and a mass1kg support two masses of 500g and 300g . determine the centre of gravity

### physics

if a 400g ball moving 1.2 m/s [north], receives an impulse that changes its direction and speed to 2.8 m/s [east], what is the change of momentum?

### Physics

A light-rail commuter train blows its 200 Hz horn as it approaches a crossing. The speed of sound is 332 m/s.

### Physics

How much work does spike do when he pulls a 50 kg sled with a force of 200 N with a rope at an angle of 30 degrees above the horizontal, 20 m?

### physics

A light-rail commuter train blows its 200 Hz horn as it approaches a crossing. The speed of sound is 330 m/s.

### Physics

A 4.12 kg mass undergoes an acceleration along both the x and y directions. Ax = -2.60 m/s2 and Ay = 3.50 m/s2. Find the magnitude of the resultant force. Answer in units of N.

### Physics

A strong lightning bolt transfers about 21.45 C to Earth. How many electrons are transferred? The elemental charge is 1.602 × 10^−19 C.