# Homework Help: Science: Physics

## Recent Homework Questions About Physics

**physics**

A body travels with uniform acceleration.Its final velocity,v=180-7x,where x is the displacement.Then find its acceleration.

**physics**

You are in a hot-air balloon that, relative to the ground, has a velocity of 5.40 m/s in a direction due east. You see a hawk moving directly away from the balloon in a direction due north. The speed of the hawk relative to you is 1.05 m/s. What are (a) the magnitude and (b)...

**Physics**

A ball is thrown vertically upward with an initial speed of 11 m/s . Then, 0.67 s later, a stone is thrown straight up (from the same initial height as the ball) with an initial speed of 25 m/s . How far above the release point will the ball and stone pass each other? The ...

**Physics**

Human feet and legs store elastic energy when walking or running. They are not nearly as efficient at doing so as kangaroo legs, but the effect is significant nonetheless. If not for the storage of elastic energy, a 70.0-kg man running at 4.00 m/s would lose about 100 J of ...

**Physics**

A velodrome is built for use in the Olympics (see the figure below). The radius of curvature of the surface is 15.9 m. At what angel should the surface be banked for cyclists moving at 15.0 m/s? Choose an angle so that no frictional force is needed to keep the cyclists in ...

**physics**

A cannon is fired horizontally from a platform . The platform rests on a flat, icy, frictionless surface. Just after the shell is fired and while it is moving through the barrel of the gun, the shell (mass 3.2 kg) has an acceleration of 12500 m/s2. At the same time, the cannon...

**Physics**

Kangaroos can easily jump as far as 8.0 m. If a kangaroo makes five such jumps westward and then seven such jumps northward, what angle would the resultant displacement vector make with the northern displacement vector? What is the magnitude of the total displacement?

**Physics College**

What is the rate of deceleration of a 1400-kg SUV that is going 75.0 km/h and then slows to 25.0 km/h in 8.20 s?

**physics**

a Baseball player throws a ball for the outfield horizontally such that it is released 1.5 meters above the ground. if the ball is to reach second base 20.0 meters away, how fast must the ball be thrown so that is does not bounce before reaching the base

**Physics (Force)**

A power wheelbarrow has a mass of 432 kg. What force must be applied to give it an acceleration of 1.75 m/s2?

**Physics**

A Boeing 747 can travel up to 254m/s. The pilot must travel from Vancouver to Calgary, which is located 3.0 x 10^2 km [N] and 7.0 x 10^2 km [E]. There is a strong wind blowing at 50.0 m/s [SE] A) determine the direction that the plane must travel to reach its destination in ...

**Physics**

I need help setting up this problem. A tennis player serves a tennis ball such that it is moving horizontally when it leaves the racquet. When the ball travels a horizontal distance of 19 m, it has dropped 58 cm from its original height when it left the racquet. What was the ...

**Physics**

I need help setting up this problem. While standing on the roof of a building, a child tosses a tennis ball with an initial speed of 15 m/s at an angle of 20° below the horizontal. The ball lands on the ground 2.8 s later. How tall is the building? Thank you.

**Physics**

Add the two component vectors from Sample Problem 1 algebraically to erify that they equal the given vector The two component vectors are: 8.6m(North) and 12m (west) The given vector is 15m(West 35 degrees North) Because when i add 8.6 and 12 it doesnt equal 15m. It should ...

**physics PLEASE HELP**

Add the two component vectors from Sample Problem 1 algebraically to erify that they equal the given vector The two component vectors are: 8.6m(North) and 12m (west) The given vector is 15m(West 35 degrees North)

**Physics**

In an experiment done by scattering 5.5 MeV α particles on a thin gold foil, students find that 10,000 α particles are scattered at an angle greater than 90 degrees. How many α particles will be scattered between 60 degrees and 80 degrees?

**physics**

calculate at what height above the earths surface a satellite must be placed if it is to remain over the same geographical point on the equator of the earth. what is the velocity of the satellite?

**physics**

In the Bohr model of the hydrogen atom, an electon mass= 9.11 x 10^-31 kg orbits a proton at a radius of 5.29 x 10^-11 m. The proton pulls on the electron with a force of 8.20 x 10^-8N. what is the speed of the electron? what is the period of the electron? I really need help ...

**Physics-Intro**

Find the total force necessary to give a rocket of mass 25,000 slugs an acceleration of 28.0 ft/s2.

**Physics help please**

In an experiment done by scattering 5.5 MeV α particleson a thin gold foil, students find that 10,000 α particles arescattered at an angle greater than 90 degrees. How many α particles will be scattered between 60 degreesand 80 degrees?

**physics**

An electron travels 2.7 m in 6.37 × 10−8 s. How fast is it traveling?

**Physics help please**

Rutherford Scattering Calculate the impact parameter for scattering a 7.7 MeV alpha particle from gold at an angle of (a) 1 degree and (b) 90 degrees?

**Physics help**

Add the two component vectors from Sample Problem 1 algebraically to erify that they equal the given vector The two component vectors are: 8.6m(North) and 12m (west) The given vector is 15m(West 35 degrees North)

**Physics Repost**

I need help setting up this problem. A tennis player serves a tennis ball such that it is moving horizontally when it leaves the racquet. When the ball travels a horizontal distance of 19 m, it has dropped 58 cm from its original height when it left the racquet. What was the ...

**Physics Repost**

I need help setting up this problem. While standing on the roof of a building, a child tosses a tennis ball with an initial speed of 15 m/s at an angle of 20° below the horizontal. The ball lands on the ground 2.8 s later. How tall is the building? Thank you.

**Physics please help**

Add the two component vectors from Sample Problem 1 algebraically to erify that they equal the given vector The two component vectors are: 8.6m(North) and 12m (west) The given vector is 15m(West 35 degrees North)

**physics**

A soccer ball is kicked at an angle of 30° to the horizontal with an initial velocity of 16 m/s. How far does the soccer ball go? A. 3.8 m B. 6.6 m C. 13.3 m D. 22.6 m i used the formula vf^2-(visin theta)^2 / 2g for this and solved it for 3.3m but none of the answers are ...

**Physics**

a boat crosses a .2mi river is heading perpendicularly relative to the shore. its speed in still water is 4mph and the speed of the current is 6mph

**Physics**

I need help setting up this problem. While standing on the roof of a building, a child tosses a tennis ball with an initial speed of 15 m/s at an angle of 20° below the horizontal. The ball lands on the ground 2.8 s later. How tall is the building? Thank you.

**Physics**

I need help setting up this problem. A tennis player serves a tennis ball such that it is moving horizontally when it leaves the racquet. When the ball travels a horizontal distance of 19 m, it has dropped 58 cm from its original height when it left the racquet. What was the ...

**Physics**

HI I'm just looking for an answer for 3 questions as my textbook does not explain the answer. How a tin can loses heat through: 1) Conduction 2) Convection 3) Radiation

**physics**

Suppose a vector V⃗ makes an angle ϕ with respect to the y axis.What could be the x and y components of the vector V⃗ ? Express your answers in terms of the variables V and ϕ separated by a comma.

**physics**

A mass pulled by a constant force accelerates from 10 cm/s to 40 cm/s in 5.5 s. A second force accelerates the same mass from rest to 105 cm/s in 15.0 s. If the first force is known to be 5.0 N, that what is the magnitude of the second force?

**physics**

A block of mass m=8 kg is held at the rest on a smooth (fiction less) 37 degree incline by a horizontal force F. the magnitude of the force F (in N) is:

**Physics**

At a time when mining asteroids has become feasible, astronauts have connected a line between their 3360-kg space tug and a 6300-kg asteroid. Using their ship's engine, they pull on the asteroid with a force of 490 N. Initially the tug and the asteroid are at rest, 430 m apart...

**Physics**

A car accelerates from rest at 5 m/s2 for 5 seconds. It moves with a constant velocity for some time, and then decelerates at 5 m/s2 to come to rest. The entire journey takes 25 seconds. On a separate sheet of paper, plot the velocity-time graph of the motion. Describe the ...

**physics**

Find the total force necessary to give a rocket of mass 25,000 slugs an acceleration of 28.0 ft/s2.

**physics**

One ball is dropped from a cliff. A second ball is thrown down 1.00 s later with an initial speed of 40.0 ft/s. How long after the second ball is thrown will the second ball overtake the first?

**physics**

A woman raises a 65N box 16m in 4 seconds.Calculate the work done by the woman on the box

**physics**

This graph in the figure (Figure 1) shows how the temperature of an initially solid sample changes as time goes by when it is placed above a flame that delivers a constant heating power (that is, a fixed amount of energy input in the form of heat each second). The process ...

**physics**

A 20kg box rests ona table and a 10kg is placed on top of the 20kg box. Determine the normal force that the table exerts on the 20kg box and the normal force that the 20kg box exerts on the 10kg box. please help

**Physics**

Which of the following are the correct units for mass?

**Physics**

You want to use a rope to pull a 12-kg box of books up a plane inclined 30∘ above the horizontal. The coefficient of kinetic friction is 0.29. The rope pulls parallel to the incline. What force do you need to exert on the rope if you want to pull the box with a constant ...

**physics**

The helicopter in the drawing is moving horizontally to the right at a constant velocity. The weight of the helicopter is W=41600 N. The lift force L generated by the rotating blade makes an angle of 21.0° with respect to the vertical. (a) What is the magnitude of the lift ...

**Physics**

A certain automobile engine delivers 2.24 ✕ 10^4 W (30.0 hp) to its wheels when moving at a constant speed of 31.0 m/s ( 69 mi/h). What is the resistive force acting on the automobile at that speed?

**Physics**

A washing machine drum has a diameter of 46 cm and spins at 400 revolutions per minute. Find the centripetal acceleration at the drum's surface. Give your answer in m/s

**physics 12**

a boeing 747 can travel up to 254m/s. The pilot must travel from vancouver to calgary, which is located 3.0x10^2km [N] and 7.0x10^2km [E]. there is strong wind blowing at 50.0m/s [SE].

**Physics**

Knowing that at the time of the release the balloon was 73.8 m above the ground, determine the time, τ, it takes the bag to reach the ground from the moment of its release.

**physics**

A 96.5 kg ice hockey player hits a 0.150 kg puck, giving the puck a velocity of 45.5 m/s. If both are initially at rest and if the ice is friction less, how far does the player recoil in the time it takes the puck to reach the goal 18.0 m away?

**physics**

A small coin, initially at rest, begins falling. If the clock starts when the coin begins to fall, what is the magnitude of the coin\'s displacement between t1 = 0.1749 s and t2 = 0.437 s?

**physics**

A man holding a rock sits on a sled that is sliding across a frozen lake (negligible friction) with a speed of 0.540 m/s. The total mass of the sled, man, and rock is 93.5 kg. The mass of the rock is 0.300 kg and the man can throw it with a speed of 15.0 m/s. Both speeds are ...

**physics**

Two ice skaters stand facing each other at rest on a frozen pond. They push off against one another and the 48-kg skater acquires a speed of 0.65 m/s. If the other skater acquires a speed of 0.84 m/s, what is her mass?

**Physics**

Nellie weighs 300 N and stands on a pair of bathroom scales. If she leans so that one-third of her weight is on the left scale, what is her reading on each scale?

**physics**

If you stand on a pair of bathroom scales, explain how the readings change as you shift your weight gradually from side to side. what rule governs the readings on the scale?

**Physics**

a) An electron in an atom has a speed of 2.2 × 10^6 m/s and orbits the nucleus at a distance of 5 × 10^-11m. What is its centripetal acceleration? (already solved) 9.68x 10^22 m/s^2 b) A neutron star of radius 17 km is found to rotate at 5 revolutions per second. What is the...

**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**

what is the mass density of mercury is 13.6g/cm^3. A cylinder of mercury has a diameter of 1 cm and a height of 76cm. what would the height of the cylinder of the water having a diameter of 1 cm and a mass equal to the mass of the mercury cylinder?

**physics**

A truck on a straight road starts from rest, accelerating at 2.00 m/s2 until it reaches a speed of 11.0 m/s. Then the truck travels for 65.0 s at constant speed until the brakes are applied, stopping the truck in a uniform manner in an additional 5.00 s. (a) How long is the ...

**Physics please help**

An ant travels 2.78 cm (West) and then turns and travels 6.25cm (south 40 degrees East). What is the ant's total displacement?

**physics**

In 10 seconds a car accelerates 3m/s^2 to 90m/s. How fast was the car going before it accelerated?

**Physics**

A police car is traveling at a velocity of 20.0 m/s due north, when a car zooms by at a constant velocity of 44.0 m/s due north. After a reaction time 0.700 s the policeman begins to pursue the speeder with an acceleration of 6.00 m/s^2. Including the reaction time, how long ...

**Physics**

rom the top of a cliff, a person uses a slingshot to fire a pebble straight downward, which is the negative direction. The initial speed of the pebble is 7.56 m/s. (a) What is the acceleration (magnitude and direction) of the pebble during the downward motion? (b) After 0.950 ...

**Physics**

A 103 kg sprinter wishes to accelerate from rest to a speed of 13.2 m/s in a distance of 19.3 m. What coefficient of static friction is required between the runners shoes and the track?

**Physics**

The electrons that produce the picture in a TV set are accelerated by a very large electric force as they pass through a small region in the neck of the picture tube. This region is 1 cm in length, and the electrons enter with a speed of 1 × 105 m/s and leave with a speed of ...

**Physics**

A renegade watermelon starts at x = 0 m and rolls at a constant velocity to x = −3.0 m at time t = 5.0 seconds. Then, it bumps into a wall and stops. Draw its position versus time graph from t = 0 s to t = 10 s.

**physics**

C Exercise 3.57 In laboratory situations, a projectile’s range can be used to determine its speed. To see how this is done, suppose a ball rolls off a horizontal table and lands 1m out from the edge of the table. Part A If the tabletop is 70cm above the floor, determine the ...

**physics**

A certain muon detector counts 600 muouns/h at an altitude of 1900m and 380/h at sea level. Given that the muon half-life at rest is 1.5×(10^-6)s, determine the speed of the muons relative to Earth, assuming they all have the same speed.

**Physics**

Calculate the megnatic force on static electron of megnatic field of 1.4 Tesla????

**Physics**

A lorry of mass 12,000kg traveling at a velocity of 15 m/s crashes into the back of a moving car of mass 1500kg, traveling at a velocity of 5 m/s. The vehicles move together after the impact. Calculate their velocity.

**Physics**

a container weighing a 1.20 x 10^4 N sits on a hydraulic press piston with can area of 0.80m^2. Compressed ir exerts a force of on the second piston which has an area of 0.30m^2 How large must this force be to support the car

**Physics**

joel is running down the newly waxed school corridor and tries to slide across the floor in this rubber shoes. The thick 1.5-cm thick rubber soles each have a cross-sectional area of 0.015m^2 and are sheared with a force of 10,000 N

**Physics**

A 20,000 kg vehicle is running at 80km/hr in a rotonda with a radius of curvature 25m compute for the centripetal force

**Physics**

A train whose speed is 100km/hr rounds a curve whose radius of curvature is 150m what is the acceleration?

**physics**

what is the centripetal force of the train in the previous problem whose speed is 27.8 m/s rounding a curve whose radius of curvature is 150m if the train mass is 8000 kg

**physics**

how to determine the amount of water in the container when you are given a 200g piece of aluminium at 90 degrees celcius is placed in a 100g glass container which holds an unknown amount of water at 20 degrees celcius .if the equilibrium temperature is 21.6 degrees celsius(...

**physics**

how to determine the amount of water in the container when you are given a 200g piece of aluminium at 90 degrees celcius is placed in a 100g glass container which holds an unknown amount of water at 20 degrees celcius .if the equilibrium temperature is 21.6 degrees celsius(...

**physics**

A 50 kg box hangs from a rope. What is the tension in the rope if a. The box is at rest? b. The box has vy = 5.0 m/s and is slowing down at 5.0 m/s2 ?

**physics**

1) The angle of elevation to the bottom of a transmission tower on a hill from an observer standing 1.8 km away from the base of the hill is 5 degrees. The angle of elevation to the top of the tower from the tower is 6.8 degrees. If the distance from the observer to the base ...

**physics**

A 42 kg girl is bouncing on a trampoline. During a certain interval after she leaves the surface of the trampoline, her kinetic energy decreases to 250 J from 520 J. How high does she rise during this interval?

**physics**

A 60.0 kg person, running horizontally with a velocity of 3.80 m/s, jumps onto a 12.0 kg sled that is initially at rest. a) Ignoring the effects of friction during the collision, find the velocity of the sled and person as they move away. b) The sled and person coast 30.0 m on...

**physics**

One object is at rest and another is moving. The two collide in a one-dimensional, completely inelastic collision. In other words, they stick together and move off with shared velocity. The speed of the object that is moving initially is 25 m/s. The masses of the two objects ...

**physics**

A 302 kg motorcycle is accelerating up along a ramp that is inclined 24° above the horizontal. The propulsion force pushing the motorcycle up the ramp is 2860 N, and the air resistance produces a force of 235 N that opposes the motion. Find the magnitude of the motorcycle’s...

**physics**

Bob, who has a mass of 75 kg, can throw a 500 g rock with a speed of 30 m/s. The distance through which his hand moves as he accelerates the rock forward from rest until he releases it is 1.0 m. a. What constant force must Bob exert on the rock to throw it with this speed? b. ...

**physics**

A car traveling in a straight line has a velocity of 3.19 m/s at some instant. After 5.4 s, its velocity is 12 m/s. What is its average acceleration in this time interval?

**Physics**

A projectile is launched upward at 26m/s at 30 degrees from the horizontal. The whole path of the projectile takes place over level ground. How much time will the projectile be in the air?

**Physics**

Which of the following are the correct units for mass? Tons, u, g, slugs, dyn, lb, oz, kg I put g, slugs, and kg but got it wrong. What part do I have wrong?

**physics**

A motorcycle has a constant speed of 21.6 m/s as it passes over the top of a hill whose radius of curvature is 100 m. The mass of the motorcycle and driver is 392 kg. Find the magnitude of (a) the centripetal force and (b) the normal force that acts on the cycle.

**physics**

A slowly moving train with 15.0- m-long flatcars is passing a station at 11.0 km/h. A person on the station platform tosses rocks onto the moving flatcars at the rate of one every second. If the first rock just hits the front edge of one car, how many rocks will fall onto that...

**physics help please**

An airplane has an air speed of 112m/s [N 20 degrees W] and has a ground speed of 106 m/s [N 25 degrees W]. Find the velocity of the wind.

**Physics help please**

A student swims at 4m/s. She is swimming from west to east across a river that's is flowing 2.2m/s [S]. A) if the river is 100 m wide, what is the quickest time that she can swim the entire width? B) how far downstream will she be? C) if she decides to go directly across the ...

**physics**

An electron in the cathode ray tube of a tele- vision set enters a region where it acceler- ates uniformly from a speed of 30100 m/s to a speed of 3.82 × 106 m/s in a distance of 2.97 cm. What is its acceleration? Answer in units of m/s2

**physics**

A hunter wishes to cross a river that is 1.0 km wide and that flows with a speed of 4.9 km/h. The hunter uses a small powerboat that moves at a maximum speed of 9.6 km/h with respect to the water. What is the minimum time necessary for crossing?

**physics**

An electron, starting from rest and moving with a constant acceleration, travels 5.8 cm in 14 ms. What is the magnitude of this acceleration? Answer in units of km/s2

**physics**

You and a friend stand on a snow-covered roof. You both throw snowballs from an elevation of 18 m with the same initial speed of 11 m/s, but in different directions. You through your snowball downward, at 40° below the horizontal; your friend throws her snowball upward, at 40...

**Physics**

A swimmer, capable of swimming at a speed of 1.44 m/s in still water (i.e., the swimmer can swim with a speed of 1.44 m/s relative to the water), starts to swim directly across a 2.21-km-wide river. However, the current is 0.840 m/s, and it carries the swimmer downstream. (a) ...

**Physics**

A student swims at 4m/s. She is swimming from west to east across a river that's is flowing 2.2m/s [S]. A) if the river is 100 m wide, what is the quickest time that she can swim the entire width? B) how far downstream will she be? C) if she decides to go directly across the ...

**Physics**

A tennis ball connected to a string is spun around in a vertical, circular path at a uniform speed. The ball has a mass m = 0.162 kg and moves at v = 4.73 m/s. The circular path has a radius of R = 0.87 m 1)What is the magnitude of the tension in the string when the ball is at...

**physics**

A radar antenna is tracking a satellite orbiting the earth. At a certain time, the radar screen shows the satellite to be 118 km away. The radar antenna is pointing upward at an angle of 58.2 ° above the ground. Find (a) the x and (b) the y components (in km) of the position ...

**physics**

An airplane has an air speed of 112m/s [N 20 degrees W] and has a ground speed of 106 m/s [N 25 degrees W]. Find the velocity of the wind.

**Physics**

A force F acts to the right on a 4.81 kg block. A 2.53 kg block is stacked on top of the 4.81 kg block and can slide on it with a coefficient of friction of 0.2 between the blocks. The table has a coefficient of friction of 0.23. The acceleration of gravity is 9.8 m/s 2 . The ...