Explore BrainMass

# Conservation of Energy

### Reaching the Bottom of an Inclined Plane First

A ball, solid cylinder and a hollow pipe all have equal masses and radii. If the three are released simultaneously at the top of an inclined plane, which will reach the bottom first? a. the cylinder b. the pipe c. the ball d. none of the listed.

### Conservation of Potential Energy due to Gravity

Two baseballs, each with a mass of 0.122 kg, are separated by a distance of 950 m in outer space. If the balls are released from rest, what speed (in m/s) do they have when their separation has decreased to 370 m? Ignore the gravitational effects from any other objects.

### Finding a Spring Constant

Assuming negligible friction, what spring constant would be needed by the spring in a "b-b gun" to fire a 10g pellet to a height of 100m if the spring is initially compressed 10cm?

### Conservation of Energy in a Roller Coaster

Suppose the roller coaster in Fig. 8-29 (attached) (h1 = 32 m, h2 = 13 m, h3 = 20) passes point A with a speed of 3.00 m/s. If the average force of friction is equal to one fifth of its weight, with what speed will it reach point B? The distance traveled is 55.0 m.

### Conservation of Energy in a Sliding Block

A 2.0 kg block slides along a horizontal surface with a coefficient of friction Âµk = 0.30. The block has a speed of v = 1.2 m/s when it strikes a massless spring head-on (as in Fig. 8-18). (a) If the spring has a force constant k = 120 N/m, how far is the spring compressed? (b) What minimum value of the coefficient of s

### Conservation of Energy Observed When Jumping on Bathroom Scales

If you stand on a bathroom scale, the spring inside the scale compresses 0.50 mm, and it tells you your weight is 665 N. Now if you jump on the scale from a height of 1.3 m, what does the scale read at its peak?

### Conservation of Energy of Pendulum Bob and Its Speed

A simple pendulum has a length of 0.75 m and a bob whose mass is 0.15 kg. The bob is released from an angle of 25 degrees relative to a vertical reference line. a) Show that the vertical height of the bob when it is released is h=L(1-cos25 degrees). b) What is the kinetic energy of the bob when the string is at an angle of 9.0 d

### Conservation of Mechanical Energy

A black of mass m=750g is released from rest and slides down a frictionless track of height h=55.2cm. At the bottom of the track the block slides freely along a horizontal table until it hits a spring attached to a heavy, immovable wall. The spring compressed by 2.64cm at the maximum compression. What is the value of the spring

### Energy - Speed

A 58 kg skier is coasting down a 25 degree slope. A kinetic frictional force of 70-N opposes her motion. Her initial speed is 3.6 m/s at the top of the slope. Ignoring air resistance, determine her speed at a point located 57m down the slope.

### Shooting the Breeze

Please do not place your response in a .pdf or .cdx format, but Word documents are okay. Thanks! Please see attached for actual problem. Note that I only need help with the last part of this problem! PSS 6.1: Shooting the Breeze Learning Goal: To practice Problem-Solving Strategy 6.1 for projectile motion problems. A stu

### Bullet Collision Momentum

A 12.0-g rifle bullet is fired with a speed of 380 m/s into a ballistic pendulum with with mass 6.00 kg, suspended from a cord 70.0 cm long. Compute the vertical height through which the pendulum rises. Compute the initial kinetic energy of the bullet. Compute the kinetic energy of the bullet and pendulum immediately after the b

### What will the final temperature of the block of iron and the water?

Place a kilogram block of iron at 40 degrees C into a kilogram of water at 20 degrees C. What will the final temperature of the two become, and why?

### Determining the Tension on the Cable and Angle

A 600 kg wrecking ball is suspended from a crane by a cable having negligable mass. If the ball has a speed v= 8m/s at the instant it is at its lowest point, theta= 0 deg., determine the tension in the cable at this instant. Also, determine the angle theta to which the ball swings before stopping. The length of the cable is 12m.

There are two main types of collisions that you will study: elastic and perfectly inelastic. In an elastic collision, kinetic energy is conserved. In a perfectly inelastic collision, the particles stick together and thus have the same velocity after the collision. There is actually a range of collision types, with elastic and pe

### Energy and springs

A block of mass M slides along a horizontal table with speed Vo. At x=0 it hits a spring with spring constant k and begins to experience a friction force. The coefficient of friction is variable and is given by Mu=b*x, where b is a constant. Find the loss in mechanical energy when the block has first come momentarily to rest

### Energy and speed in circular motion

A pendulum is pulled over by a distance R. The pendulum has a mass of 15.1kg 1) Compute the work done by pulling the pendulum to this point. Next the pendulum is given a push so it circles its neutral position along the radius R. 2) Find the kinetic energy of the circling pendulum The length of the string is "l" and R

### Find the instantaneous elongation and stress in the bar

A mass of 336 kg falls through a distance of 17.5mm on to the stop at the lower end of a vertical steel bar which is 5.2 metres long and 735 square mm in cross section area. If the modulus of elasticity is equal to 210 GPascals for the bar, find a) instantaneous elongation b) the stress in the bar Please provide detai

### Heat exchange occurs between three objects

An aluminum rod has a mass of 4.5 kg and is initially at room temperature of 23 degrees Celsius. The rod is dropped into an aluminum tank whose mass is 1.22 kg, containing an unknown mass of water. The tank and the water are at 96 degrees Celsius. Heat exchange occurs only between the rod, the tank and the water, all of which e

### Energy Conservation and Thermodynamical Cycles

An ideal gas initially at pressure Po, volume Vo, and temperature To is taken through the cycle described in attached file. A) Find the net work done BY the gas per cycle in terms of Po and Vo. I believe that my answer of 2Po2Vo is correct. B) What is the net energy Q added to the system per cycle? I know that I ha

### Adiabatic process and the equation of state.

A sample of 8.02 x 10^-1 moles of nitrogen gas (gamma=1.40) occupies a volume of 2.00 x 10^-2 m^3 at a pressure of 1.00 x 10^5 Pa and temperature 300K. the sample is adiabatically compressed to half its original volume, nitrogen behaves as an ideal gas under these conditions. Show from the adiabatic condition and the equation of

### Potential Energy

A 5.00-kg block free to move on a horizontal, frictionless surface is attached to one end of a light horizontal spring. The other end of the spring is held fixed. The spring is compressed 0.100 m from equilibrium and released. The speed of the block is 1.20 m/s when it passes the equilibrium position of the spring. The same

### Physics around an Object Towed up and Incline

An object on an incline of 30 degrees is towed up the incline by an applied force of 100N. The coefficient of kinetic friction of mu=.35. The mass of the object is 10.0kg. PART I 1) Draw a sketch 2) Draw a free body diagram 3) What is the weight of the object? 4) What is the acceleration of the object in the y direction?

### What is the speed of the block just before it hits the spring?

A 500 g block is dropped onto a relaxed vertical spring with a spring constant k = 3 N/cm. The block becomes attached to the spring and continues downward under the influence of gravity, compressing the spring 15 cm before momentarily stopping. What is the speed of the block just before it hits the spring?

### Flow in a Pipe using Conservation of Mass

See the attached file for the problem.

### Conservation of energy in a spring-masses system

Please see attachments, weights are in pounds force not pounds mass. Blocks A and B weigh 8lb and 3lb respectively and are connected by a cord-pulley system and released from rest with the spring undeformed. knowing the spring constant K determine the velocity of block B after it has moved 6 inches. The find the maximal veloc

### Working with Boxes going down a belt

Boxes are transported by a conveyor belt with a velocity v_0 to a fixed incline at A where they slide and eventually fall off at B. Knowing that u_k=0.40, determine the velocity of the conveyor belt if the boses leave the incline at B with a velocity of 2m/s.

### Momentum in 2 dimensions

The picture (attached) shows two pucks about to collide and one of them after the collision, what is the velocity (Magnitude and Direction) of the .4 kg puck after the collision? (The point of the question is to use the conservation of momentum equations) Two blobs of clay have the initial velocities shown below. The velocit

### speed of a golf ball when it is 8.0m below its highest point

A 47.0-g golf ball is driven from the tee with an initial speed of 52.0 m/s and rises to a height of 24.6 m. (a) Neglect air resistance and determine the kinetic energy of the ball at its highest point. (b) What is its speed when it is 8.0 m below its highest point?

### Energy Theorem and Kinetic Energy: Coefficient of Friction

Question: A 16-kg sled is being pulled along the horizontal snow-covered ground by a force of 24 N. Starting from rest, the sled attains a speed of 2.0 m/s in 8.0 m. Find the coefficient of kinetic friction between the runners of the sled and the snow.

### Compressed Springs and Conservation of Momentum

"A spring of negligible mass is compressed between two masses on a frictionless table with upward sloping ramps at each end. The masses are released simultaneously. The mass of M1 is less than the mass of M2. A) Is the force exerted by the spring on M1 greater than, equal to, or less than the force it exerts on M2? B) Is the