# Anu

### can someone help me with these?

1) A timekeeper standing on the finish line of a 100 m race starts his stopwatch when he hears the bang from the starting gun fired at the starting line. Calculate the error in his measurement if the speed of sound is 345 m/s.

2)Standing at a distance from a mountain cliff you clap and hear an echo. You continue clapping your hands and adjust the frequency of clapping to the echoes so that you can no longer hear the echo. At this point you are clapping at the same time you hear the echo. Determine the distance between you and the cliff if you are clapping every 1.1 s and the speed of sound is 340 m/s.

1 AnswerPhysics2 weeks ago### help please?

Sir Isaac Newton predicted a speed of sound that was tested by William Derham in 1709. Derham used shotguns fired from church towers near London, England that were 20.1 km apart. By watching for the flash of the gun firing and listening for the sound of its blast he was able to calculate a precise value for the speed of sound. In one test, he found the time between the flash of the gun and hearing the sound to be 57.8s. Calculate the speed of sound.

4 AnswersPhysics2 weeks ago### physics help?

Determine the magnitude of the gravitational field at a distance of 12.0 m away from a 100 kg mass.

1 AnswerPhysics2 weeks ago### physics circular motion and gravitation?

Calculate the factor by which the gravitational force between two objects would change if

a) The distance between them was doubled.

b) Both masses are tripled and the distance is reduced to one quarter of its original amount.

4 AnswersPhysics3 weeks ago### physics help?

1. If a satellite orbits Earth with an orbital radius (distance from the center of the Earth) of 9.25x106 m, determine the satellite’s

a) Orbital speed.

b) Time (in hours) to go around the Earth once.

1 AnswerPhysics3 weeks ago### physics help?

The distance between bases on a professional baseball diamond is 27.4m. Amy is the batter and gets a hit. She runs due west to first base then turns due south and runs to second base where she stops. Determine the displacement of second base relative to home plate.

3 AnswersPhysics3 weeks ago### vectors physics?

The distance between bases on a professional baseball diamond is 27.4m. Amy is the batter and gets a hit. She runs due west to first base then turns due south and runs to second base where she stops. Determine the displacement of second base relative to home plate.

2 AnswersPhysics3 weeks ago### physics help?

Not only did the pendulum provide the first effective means of measuring time, it also allowed for the metre to be standardized in a way that allowed anyone anywhere to easily determine a metre’s length. Explain how this could be important for those involved in buying and selling items that are sold by length or volume.

Physics3 weeks ago### physics oscillator motion?

A 110 g. mass on a spring oscillates on a frictionless horizontal surface with a period of 0.60 s. and an amplitude of 18.0 cm. Determine the

Spring constant.

Maximum spring potential energy of the system.

Maximum speed of the mass.

2 AnswersPhysics3 weeks ago### physics (oscillatory motion)?

Simple harmonic motion is characterized by a force that restores an object to equilibrium. The magnitude of the force changes as the size of the oscillation changes. Identify the source of the restoring force for a:

Swinging pendulum.

Vertically hung spring oscillating up and down.

1 AnswerPhysics3 weeks ago### energy physics?

A 10.0 kg box is pushed up a frictionless incline 4.0 m long. The surface inclined at 30° relative to the horizontal. Determine the amount of work being done on the box to push it at a constant speed all the way up the inline.

A IM-B Bomarc missile was used by Canada as a surface-to-air missile (SAM) in the 1960s. It had a mass of 7250 kg and could travel close to three times the speed of sound. Determine the kinetic energy of the Bomarc missile with a velocity of 942 m/s.

2 AnswersPhysics4 weeks ago### physics vectors?

The distance between bases on a professional baseball diamond is 27.4m. Amy is the batter and gets a hit. She runs due west to first base then turns due south and runs to second base where she stops. Determine the displacement of second base relative to home plate. Show your work.

3 AnswersPhysics4 weeks ago### help needed?

A sign is suspended by two wires . Determine the tension in each wire when one side is 35 degrees and the other is 55 degrees. the mass is 100kg.

4 AnswersPhysics4 weeks ago### does anyone know how to do this?

A ferry boat has a speed of 5.0 km/h in calm water. Its pilot takes it on a heading due north across a river that has a current of 2.0 km/h west. It takes 20 minutes to cross the river. Calculate and show your work.

a) The rivers width.

b) How far downstream the boat lands.

c) The boat’s velocity relative to the shore.

1 AnswerPhysics4 weeks ago### physics help?

A driver in a car traveling at 14.1 m/s along a level but icy road steps on the brakes. The wheels lock and the tires skid along the icy surface for a distance of 24.6m before coming to a stop. Calculate the coefficient of friction between the car’s tires and the ice.

Newton’s third law describes partially how the lift force is produced. The wing is shaped to direct air downwards from the underside of the wing but not upward from the topside of the wing. Use newton’s third law to explain how this produces the lift force. (for more explanation about the lift created read about Bernoulli’s principle)

3 AnswersPhysics1 month ago### I don't understand this question?

2 AnswersPhysics1 month ago### i need help with this. its just a lot calculations?

1 AnswerChemistry2 months ago### help me please!!!?

25.0 mL of 0.150 mol/L KBr(aq) is mixed with excess Pb(NO3)2(aq)

Write the balanced chemical equation for this reaction.

Calculate the number of moles of limiting reagent.

Predict the number of moles of precipitate. (Solubility table unit A to determine which one is insoluble)

Calculate the mass of precipitate.

2 AnswersChemistry2 months ago### Gas Stoichiometry?

How many liters of oxygen at STP are needed to react with 5.2×10 22 molecules of hydrogen sulfide? __ H2S + __ O2 → __ SO2 + __ H2O 7. What volume of nitrogen gas at STP is produced when 68.2 g of trinitrotoluene,

C7H5(NO2)3reacts?__C7H5(NO2)3 → __ C + __ CO + __ H2 + __ N2

Chemistry2 months ago