# Homework Help: Science: Physics

## Recent Homework Questions About Physics

**physics**

Only two forces act on an object (mass=3.19 kg), as in the drawing. Find (a) the magnitude and (b) the direction (relative to the x axis) of the acceleration of the object.

**physics**

An apple crate with a weight of 225 N accelerates along a frictionless surface as the crate is pulled with a force of 14.5 N as shown in the drawing. What is the horizontal acceleration of the crate?

**physics**

A mountain climber, in the process of crossing between two cliffs by a rope, pauses to rest. She weighs 520 N. As the drawing shows, she is closer to the left cliff than to the right cliff, with the result that the tensions in the left and right sides of the rope are not the ...

**physics**

During a storm, a tree limb breaks off and comes to rest across a barbed wire fence at a point that is not in the middle between two fence posts. The limb exerts a downward force of 253 N on the wire. The left section of the wire makes an angle of 15.4° relative to the ...

**physics**

One block rests upon a horizontal surface. A second identical block rests upon the first one. The coefficient of static friction between the blocks is the same as the coefficient of static friction between the lower block and the horizontal surface. A horizontal force is ...

**physics**

Traveling at a speed of 18.0 m/s, the driver of an automobile suddenly locks the wheels by slamming on the brakes. The coefficient of kinetic friction between the tires and the road is 0.580. What is the speed of the automobile after 1.44 s have elapsed? Ignore the ...

**physics**

A person pushes on a 55-kg refrigerator with a horizontal force of -250 N; the minus sign indicates that the force points in the -x direction. The coefficient of static friction is 0.56. (a) If the refrigerator does not move, what are the magnitude and direction of the ...

**physics**

A car is traveling up a hill that is inclined at an angle θ above the horizontal. Determine the ratio of the magnitude of the normal force to the weight of the car when (a) θ = 17o and (b) θ = 30o

**physics**

when an apple falls from a tree, and strikes the ground without bouncing, what happens to its momentum?

**Physics**

A 100 grams mass of a substance has a volume of 150 centmetre cube.Calculate the relative density of the substanc. [density of water pw=1.0gcm^-3]

**Physics**

An alloy of iron and silver has a total mass of 30 grams and a volume of 20.4cm^-3.Calculate the mass of iron only and the volume of silver only. [Density of iron=1.62gcm^3 and density of silver=0.9gcm^3]

**Physics**

A piece of metal of volume 250 centimetre cube floats in water when 85 percent of its volume is under water.Calculate the upthrust on the metal. [pw=1.0gcm^-3]

**Physics**

An empty bottle weighs 20 grams and 60 grams when filled completely with water.What would the bottle weigh when filled completely with mercury. [pw=1.0gcm^-3,pm=1.6gcm^-3]

**physics**

when temperature increases from t to # t and the moment of inertia is increase from I to #I. the coefficent of linear expansion is alpha .THE RATIO OF #I\I IS

**Physics**

A ball thrown with a speed of 100m/s attains a height of 150m (take g=9.8 per second square). Calculate: 1. Time of flight 2. Angle of projection 3. Range

**Physics**

What is specific heat

**Science(physics)**

A boy while driving to his school covers at the average speed of 15km/h.On his return trip along the same route, covers at the average speed of 25km/h due to less traffic.What is the average speed for the whole trip

**Physics**

The engineer of a passenger train moving at 29.0 m/s sees a freight train 360.m ahead on the track moving at 6.00 m/s. The engineer takes 0.400 seconds to react, and then applies the brakes. At what rate must the passenger train then decelerate in order to avoid a collision? ...

**Physics**

A 55kg person pushes on the floor with 800 N of force for 0.25 seconds. How high do they jump off the ground? I know how to find acceleration but I can't find distance.

**Physics**

An alloy of iron and silver has a total mass of 30 grams and a volume of 20.4 centimetre cube Calculate the mass of iron only and the volume silver only Please help

**Physics**

A piece of metal of volume 250 cetimetre cube floats in water when 85 percent of it's volume is under water.Calculate the upthrust on the metal. 250*85=21250

**Physics**

An empty bottle weighs 20g and 60g when filled completely with water.What will it weigh when filled completely with mercury? 20÷60=0.3

**Physics**

A student eats a dinner containing 8.0x10 raised to power 6j of energy. He wishes to do an equivalent amount of work in a nearby gym by lifting a 60kg object. How many times must he raise the object to expand this much energy? Assume that he raises it a distance of 2.0m each ...

**physics**

a runner in marathon passes the 5 mile mark at 1 o'clock and the 20 mile mark at 3 o'clock .what is the runners average speed during this time period?

**physics**

A passengers jet flies from one airport to another 1,200 miles away in 2.5h .Find its average speed.

**physics**

How far does a car going 25 m/s travel in 5s ? How far would a jet going 250 m/s travel in 5s?

**Physics**

Find the specific heat of an unknown metal given this data: Mass of the metal = 120 g Temp of the metal = 220 degrees Mass of the water = 30 g Initial Temp of the water = 20 degrees Final Temp of the water = 85.6 degrees Specific Heat of the water = 4.186 J/gram C I get 0.51 J...

**physics**

ifv=(3i+4j+5k)m/s is the instantaneous velocity of a body mass 1.50kg calculate its K.E

**physics**

An ostrich with a mass of 139 kg is running to the right with a velocity of 17 m/s. Find the momentum of the ostrich. Answer in units of kg · m/s.

**physics**

A car is traveling up a hill that is inclined at an angle θ above the horizontal. Determine the ratio of the magnitude of the normal force to the weight of the car when (a) θ = 17o and (b) θ = 30o.

**Physics**

:( physics:(

**Physics**

A 70.0-kg astronaut pushes to the left on a spacecraft with a force in "gravity-free" space. The spacecraft has a total mass of 1.0 × 104 kg. During the push, the astronaut accelerates to the right with an acceleration of 0.36 m/s2. Determine the magnitude of the ...

**physics**

When a parachute opens, the air exerts a large drag force on it. This upward force is initially greater than the weight of the sky diver and, thus, slows him down. Suppose the weight of the sky diver is 869 N and the drag force has a magnitude of 1096 N. The mass of the ...

**physics**

Two skaters, a man and a woman, are standing on ice. Neglect any friction between the skate blades and the ice. The mass of the man is 84 kg, and the mass of the woman is 49 kg. The woman pushes on the man with a force of 58 N due east. Determine the acceleration (...

**physics**

In a quarter-mile drag race, two cars start simultaneously from rest, and each accelerates at a constant rate until it either reaches its maximum speed or crosses the finish line. Car A has an acceleration of 11.0 m/s2 and a maximum speed of 110 m/s. Car B has an acceleration ...

**physics**

An electron is a subatomic particle (m = 9.11 x 10-31 kg) that is subject to electric forces. An electron moving in the +x direction accelerates from an initial velocity of +7.62 x 105 m/s to a final velocity of 2.56 x 106 m/s while traveling a distance of 0.0778 m. The ...

**physics**

Can someone please help me? I am having a really hard time with physics. This is not a test question. It is a practice problem from a review website I am supposed to use, but I am having a really hard time. Can someone at least help me to begin setting up the problem? I would ...

**College Physics**

Two forces and are applied to an object whose mass is 5.75 kg. The larger force is . When both forces point due east, the object's acceleration has a magnitude of 0.979 m/s2. However, when points due east and points due west, the acceleration is 0.639 m/s2, ...

**physics**

a ball is thrown Vatican upward with a velocity of 20.0m/s. a) what is the retardation of the ball? b) what distance does it travel before its comes to rest movementally at the top of its motion? c) what is the time taken for the ball to reach its highest point? d) what is the...

**physics (mechanics)**

the potential energy of a system of two particle separated by a distance r is given by u(r) = A/r , where A is constant . find the radial force Fr that each particle exerts on the other

**College Physics**

An airplane has a mass of 3.19 × 104 kg and takes off under the influence of a constant net force of 1.56 × 104 N. What is the net force that acts on the plane's 82.1-kg pilot?

**Physics**

Draw a block and tackle system of pulleys with a velocity ratio of 5.A block and tackle with a velocity ratio of 5 is used to raise a mass of 25kg through a vertical distanceof 40cm at a steady rate. If the efforts is equal to 60N, determine a)d distance moved by the effort b)...

**Physics**

3. What happens to the speed of ocean waves as they come close to shore? How can this be explained from what you've learned so far? (this the teacher means what do the lessons have to do with this question) 4. Sound travels faster through wood than through air. Sound also ...

**physics**

A small tiny nail may Pierce an inflated Tyre and remain there without pressure reduction.explain

**physics**

A man holds a child on shoulders while watching a football match. How much work has he done if the game last for 2 hours

**Physics**

Hello, can someone please check my answers and tell me if they are correct? 1. A laser produces a pulse of light with a speed of 300000000m/s in vacuum in a time 1.70x10^-15s. a) what is the length of the pulse? b) The pulse travels into a piece of glass in which it's lenghth ...

**Physics, math, algebra**

How long will it take a sled to reach the bottom of a hill, if it accelerates at 5.60m/s^2 and has a final velocity at the bottom of the hill of 42.3km/h?

**Physics**

Please help with the following question: You are on a planet whose radius is known to be about 4500 km. You then perform the following experiment: You drop a rock from a height of 10.0 m and measure the time of its fall to be 2.65 s. What is the mass of the planet? what ...

**Physics**

when tuning a piano, amusician plays a note that should be at 110Hz while at the same time tapping a 110Hz tuning fork and holding it next to the strings. He hears beats at 4Hz. (A) state and explain what frequencies the piano could be producing (b) explain how the musician ...

**Physics**

when tuning a piano, amusician plays a note that should be at 110Hz while at the same time tapping a 110Hz tuning fork and holding it next to the strings. He hears beats at 4Hz. (A) state and explain what frequencies the piano could be producing (b) explain how the musician ...

**Physics**

3. What happens to the speed of ocean waves as they come close to shore? How can this be explained from what you've learned so far? (this the teacher means what do the lessons have to do with this question) 4. Sound travels faster through wood than through air. Sound also ...

**physics**

a brass rod is 2m long at a certain temperature. What is its length for a temperature rise of 100k, if the expansivity of brass is 18*10

**Physics 1**

a skier of mass 70.0kg is pulled up a slope by a motor-driven cable. How much work is required to pull the skier 60.0 m up a 35.0 degree slope (assumed to be frictionless) at a constant speed of 2.0m/s? The Value of g is 9.81 m/s^2?

**Physics**

the coefficient of kinetic friction between both blocks and the table is .200. determine the accelerations of blocks A and B each of which has a mass of 5.0kg The diagram shows a table with two blocks labeled A and B on them. A is connected to a rope that goes over a pulley ...

**Physics**

5. If a wave has a wavelength of 20m and a speed of 100 m/s, what is the period of the oscillation? v = wavelength / period 100 = 20 / period 100*20 = periodperiod = 20 / 100 2000 s = period OR period = 20 / 100 period = 0.2 s I don't know which one is correct, please help?!

**physics**

2)A wave is represented by the equation y =2sin.pi(0.5x - 200t) where all distance are measured in centimeters and time in seconds. For this wave, calculate the : (a) frequency (b) wave length (c) speed (d) amplitude step plz

**physics help me plz**

A man at the back of a crowd watches a parade by holding a plane mirror just above his head and the parade passes 6m behind his head and the mirror is 0.25m in front of the man. How far does the image appear to be from the man... help i need solution

**Physics**

Water is falling on turbine at a rate of 6000 kg/min the height of fall is 100 m what is the power given to turbine?

**Physics**

A brass is 2m long at a certain temperature.what is its length for a temperature rise of 100k if the expansivity of brass is 18×10^6k^1

**physics**

a woman is draining her fish tank by siphoning the water into an outdoor drain the rectangular tank has footprint area A and depth H . the drain is located a distance D below the surface of the water in the tank , where D>>H . the cross section area of the siphon tube is...

**Physics**

A bullet of mass 20gm penetrates a board of thickness 10cm and mass 1kg at rest. If the board is free to move,find the thickness to which the bullet will penetrate. I used conservation of momentum to find the combined velocity of bullet and the board in terms of the initial ...

**Physics**

The focal length of a small concave mirror is 2.5cm in order to use this mirror by dentist .The distance of tooth from mirror is

**Physics**

The occupants of a car traveling at a speed of 30 m/s note that on a particular part of a road their apparent weight is 15% higher than their weight when driving on a flat road. a. Is that part of the road a hill or a dip? b. What is the vertical curvature of the road? Please ...

**Physics**

Boxes are moved on a conveyor belt from where they are filled to the packing station 11.3m away. The belt is initially stationary and must finish with zero speed. The most rapid transit is accomplished if the belt accelerates for half the distance, then decelerates for the ...

**Fun Physics**

A box is given a push up a 16.1° incline. When it reaches the bottom again it is only going 0.59 its original speed. Find the coefficient of kinetic friction. *I know the answer is .06 but I don't know how!

**Physics**

Calculate the pressure due to water experienced by a diver working 25m below the surface of water in dam.(density of water is 1g/cm3 and g=10N/kg.

**Physics**

A man can row a boat at a speed of 2metres per second . The man set out to row the boat in a river from A to B. The water in the river flows 0.8metres per second in the opposite direction.Determine the velocity of the boat through the water.

**physics**

a body is allowed to slide down a frictionless track from rest under gravity . The track end in a circular loop of diameter D . What should be the minimum height of the body in terms of D so that the body successfully complete the loop.

**physics**

a stone is dropped down a well if it takes 5s to reach the surface of the water calculate how deep the well is , what is the velocity when it reaches the surface of the water

**physics**

A body of mass 10 kg is moving with uniform velocity 20m/sec. Calculate its velocity if it enters in a black hole?

**Business mathematics**

In an examination of certain number of candidates 18 passed mathematics, 17 passed physics, 11 passed both mathematics and physics, 1 failed both subjects. Find the number of candidates that passed. i. Mathematics only. ii. Physics only. iii. Total number of candidates that ...

**physics**

How much work must an ideal refrigerator perform to make 1 kg of ice at -10C from 1 kg of water at 20C when 20C is also its exhaust temperature?

**Physics**

what metal is it if, it is 7.14g/mL => Cast Iron.

**Physics**

I understand this question: 4. If a pendulum completes 40 vibrations in a minute, what is its period? The period is the time for one complete cycle, and if the pendulum takes one minute (or 60 seconds) for 40 vibrational cycles, then it must take 1.5 seconds for one complete ...

**Physics**

If a man travels 7km N 40degree W and 10km East, find the resultant displacement.

**physics**

a Coper wire with wire with a diameter of 1.5mm is joined to an alluminium wire, which has a diameter of 2.3mm. The wire carries a current of 1.2A. What is the current density in each wire?

**Physics**

Two blocks of masses 2.9kg and 3.9 kg are held by string upper and lower and given the acceleration 0.2 in upward direction gind tension

**Physics**

Hello, I really don't get something about work and I would like that someone help me, Please. .. Well I have an exercise about two objects that are connected by an ideal rope that pass through a pulley that has a moment of inertia, so my problem is: when I use "energy" to get ...

**Physics**

Work done by conservative forces change only A)PE of the system B)KE of the system C) ME of the system D)None of these

**Physics**

A simple pendulum is oscillating with an angular amplitude 60°.If mass of bob is 50 gram the tension in the string at mean position is(g=10m/s2)

**physics**

A boat of mass 40 kg is at rest.A dog of mass 4 kg moves in the boat with a velocity of 10 m/s.what is the velocity of the boat?

**Physics**

Capacitor c1 and c2 are 4f and 2f respectively are charged as series combination across 100v battery. The two capacitors are disconnected from each other.They are connected +ve plate to +ve plate and -ve plate to -ve plate.calculate the resulting charge on each capacitor

**physics**

Geostationary satellites are placed on orbits of radius 4.2×10^4m use this information to deduce g, the acceleration of freely falling body, at this height.

**Physics**

How long does it take for sound to travel around the world ?

**Science (physics)**

The driver of a car travelling along a straight road with a speed of 72km/hour observe a signboard which give a speed limit to be 54 km/hour. The sign board is 70m ahead when the driver applies the break calculate the acceleration of the car which will cause the car to pass ...

**Physics**

Describe a vibration that is not periodic. I'm not sure how to answer this! Please help?!

**physics**

What should be the minimum initial velocity with which a missile has to be launched so that it reaches a target of 1000km away in the same plane

**physics**

A geostationary satellite for communications seems to be in a fixed spot above the equator because it has the same angular velocity as the earth.A) show that if it goes round once a day,its angular velocity is a little over 7Ã—10 race to negative 5 rad per second

**Physics**

A lump of lead with mass 0.5kg is dropped from height of 20m onto a hard surface it doesn't rebound but remains there at rest for a long period of time. A, find change in heat , change in work, change in internal energy for the lead during this process?

**physics**

A pendulum suspended from the roof of a bus moving along a horizontal track makes an angle of 5° with the vertical,,,determine the acceleration of the bus?

**physics**

A child of mass 40kg jumps off a wall and hits the ground at 4m/s he bends his knees and stops in 1s calculate the force required to slow him down how would this force be different if he didn't bend his knees and stopped in 0.1s

**Science: Physics**

We use an electric immersion heater to heat 2,0 liters water having temperature of 20C to the boiling point. Specific heat capacity of water is 4,19 kJ/(kg c). The power of the heater is 1,50 kW and efficiency of heating is 80 %. How much time does the heating take?

**Science: Physics**

An electric heater of power 2500 W is connected to a voltage of 230 V. i) Calculate the electric current going through the heater. ii) What is the resistance of the heater? iii) How much energy does it consume in a year, if it is switched on 15 min every day. iv) How much it ...

**Physics**

A lump of lead with mass 0.5kg is dropped from height of 20m onto a hard surface it doesn't rebound but remains there at rest for a long period of time. A, find change in heat , change in work, change in internal energy for the lead during this process?

**Physics**

1. A rectangular coil 0.065 m by 0.080 m is positioned so that its cross-sectional area is perpendicular to the direction of a magnetic field. The coil has 66 turns and a total resistance of 7.6 Ω and the field decreases at a rate of 2.5 T/s. What is the magnitude of the ...

**Physics**

A 50 N box is pushed 5 m up a 30 degree inclined plane. What work is done on the box?

**physics**

Heather and Jerry are standing on a bridge 51 m above a river. Heather throws a rock straight down with a speed of 17 m/s . Jerry, at exactly the same instant of time, throws a rock straight up with the same speed. Ignore air resistance. How much time elapses between the first...

**Physics -HELP**

1. A rectangular coil 0.065 m by 0.080 m is positioned so that its cross-sectional area is perpendicular to the direction of a magnetic field. The coil has 66 turns and a total resistance of 7.6 Ω and the field decreases at a rate of 2.5 T/s. What is the magnitude of the ...

**Physics -HELP**

A rectangular coil 0.065 m by 0.080 m is positioned so that its cross-sectional area is perpendicular to the direction of a magnetic field. The coil has 66 turns and a total resistance of 7.6 Ω and the field decreases at a rate of 2.5 T/s. What is the magnitude of the ...

**Physics -HELP**

A coil with 337 turns of wire, a total resistance of 47 Ω, and a cross-sectional area of 0.35 m2 is positioned with its plane perpendicular to the field of a powerful electromagnet. What average current is induced in the coil during the 0.30 s that the magnetic field drops ...