Welcome to lil-help. A Q&A site for homework help.

HCS 438 Week 2 Quiz Question

What is the range of the values 2.0, 3.7, 4.9, 5.0, 5.7, 6.7, 8.5, and 9.0?

Asked 7 days ago by MelS

Specific Heat and Calorimetry

A 97.6 g lead ball is dropped from rest from a height of 50 m.  The collision between the ball and the ground is totally inelastic.  Assuming all the ball's kinetic energy goes into heating the ball, find its change in temperature.

Asked 8 days ago by LanceJ

For telecommunications, satellites are better served by rotating around the earth at the same speed as the earth rotates

For telecommunications, satellites are better served by rotating around the earth at the same speed as the earth rotates, or 24.0 h.  What is the distance from the center of the Earth that the satellite must be placed to achieve this geosynchronous orbit?  What is the orbital speed of the satellite?

Asked 9 days ago by LanceJ

A potter's wheel moves from rest to an angular speed of 0.20 rev/s in 30 s

A potter's wheel moves from rest to an angular speed of 0.20 rev/s in 30 s.  Find its angular acceleration in radians per second per second.

Asked 9 days ago by LanceJ

The tires on a new compacy car have a diameter of 2.0 ft and are warranted for 50,000 miles.

The tires on a new compacy car have a diameter of 2.0 ft and are warranted for 50,000 miles.  (a)  Determine the angle (in radians) through which one of these will rotate during the warranty period.  (b)  How many revolutions of the tire are equivalent to your answer in (a)?

Asked 9 days ago by LanceJ

An explanation of Impulse

Can you tell me a little bit about Impulse for my physics assignment?

Asked 9 days ago by LanceJ

A skier of mass 70 kg is pulled up a slope by a motor driven cable. (a) How much work is required to pull him 60 m

A skier of mass 70 kg is pulled up a slope by a motor driven cable.  (a)  How much work is required to pull him 60 m up a $30^o$ slope (assumed frictionless) at a constant speed of 2.0 m/s?  (b)  What power must a motor have to perform this task?

Asked 9 days ago by LanceJ

The electric motor of a model train accelerates the train from rest to 0.620 m/s in 21.0 ms

The electric motor of a model train accelerates the train from rest to 0.620 m/s in 21.0 ms.  The total mass of the train is 875 g.  Find the average power delivered to the train during its acceleration.

Asked 9 days ago by LanceJ

A 0.250-kg block is placed on a light vertical spring $k = 5.00 \times 10^3 \text{ N/m}$ and pushed downwards, compressing the spring 0.100 m.

A 0.250-kg block is placed on a light vertical spring $k = 5.00 \times 10^3 \text{ N/m}$ and pushed downwards, compressing the spring 0.100 m.  After the block is released, it leaves the spring and continues to travel upwards.  What height above the point of release will the block reach if air...

Asked 9 days ago by LanceJ

You are given a uniform flexible chain whose mass is 5 kg and length is 5m, and a small frictionless pulley whose circumference is negligible compares to the length of the chain

You are given a uniform flexible chain whose mass is 5 kg and length is 5m, and a small frictionless pulley whose circumference is negligible compares to the length of the chain.  Initially the chain is hung over the pulley with nearly equal lengths on both sides, but just unequal enough so that...

Asked 9 days ago by LanceJ

On a frozen pond, a 10-kg sled is given a kick that imparts to it an initial speed of $v_0$ = 2.0 m/s

On a frozen pond, a 10-kg sled is given a kick that imparts to it an initial speed of $v_0$ = 2.0 m/s.  The coefficient of kinetic friction between sled and ice is $\mu_k$ = 0.10.  Use the work-energy theorem to find the distance the sled moves before coming to rest.

Asked 9 days ago by LanceJ

A block of mass 3.0 kg is pushed 5.0 m along a frictionless horizontal table by a constant 20.0 N force directed 25

A block of mass 3.0 kg is pushed 5.0 m along a frictionless horizontal table by a constant 20.0 N force directed $25^o$ below the horizontal.  Determine the work done by a) the applied force, b) the normal force exerted by the table, c) the force of gravity, and d) the net force on the block.

Asked 9 days ago by LanceJ

A basketball player 2.0 m tall want to make a basket from a distance of 9.0 m. The hoop is at a height of 3.0 m

A basketball player 2.0 m tall want to make a basket from a distance of 9.0 m.  The hoop is at a height of 3.0 m.  If he shoot the ball (from a height of 2.0 m) at a 30o angle, at what initial speed must he throw the basketball so that it goes through the hoop without striking the backboard? ...

Asked 9 days ago by LanceJ

HCS 438 Week 2 Quiz Question

In a Gallup poll of 1,038 adults, 540 said that second-hand smoke is very harmful. What is the percentage of adults who said second-hand smoke is very harmful?

Asked 10 days ago by MelS

Great Pyramid Geometry

The Great Pyramid outside Cairo, Egypt has a square base measuring 756 feet on a side and a height of 480 feet. A] What is the volume of the great pyramid in cubic yards? B] The stones used to build the Great Pyramid were limestone blocks with an average volume of 1.5 cubic yards. How many of...

Asked 10 days ago by Gigi

Describe the Easter Offensive

Describe the Easter Offensive? Include in your discussion (1) North Vietnam's goals (2) tactical results on both North Vietnamese and South Vietnamese military forces, and (3) the political consequences.

Asked 10 days ago by MelS

Nixon: Peace through Coercion

The author stated that Nixon attempted to achieve "peace through coercion". First, describe his diplomatic and military moves. Second, summarize his public strategy?

Asked 10 days ago by MelS

Difference between

Describe the difference between "positive reinforcement" and "negative reinforcement." Half-page, single spaced with one real-life example

Asked 10 days ago by MelS

B.F. Skinner

B. F. Skinner is a famous psychologist. What is/was his great contribution to science?

Asked 10 days ago by MelS

Volume and Surface Area

Firewood is measured and sold by the cord. A cord of wood is a rectangular pile of wood 4 feet wide, 4 feet high, and 8 feet long. Therefore, one cord of wood is 128 cubic feet. A cord of seasoned almond wood costs $210. How much should you pay for a pile of wood that is 4 feet wide, 3 foot... Asked 11 days ago by Gail 1 answers and 18 views Transform each test score to a z-score The mean for statistics test scores is 65 and the standard deviation is 7.0. For the biology test scores, the mean is 22 and the standard deviation is 3.8. The test scores of a student who took both tests are given below. A student gets a 75 on the statistics test and a 24 on the biology... Asked 12 days ago by hartley 1 answers and 12 views The mean value of land and buildings per acre from a sample of farms is The mean value of land and buildings per 1 acre from a sample of farms is$\$1300$, with a standard deviation of $\$200$. The data set has a bell-shaped distribution. Using the empirical rule, determine which of the following farms, whose land and building values per acre are given, are unusual... Asked 12 days ago by hartley 1 answers and 12 views Heights of men on a baseball team have a bell-shaped distribution with a mean Heights of men on a baseball team have a bell-shaped distribution with a mean of 186 cm and a standard deviation of 8 cm. Using the empirical rule, what is the approximate percentage of the men between the following values? a. 162 cm and 210 cm b. 178 cm and 194 cm Asked 12 days ago by hartley 1 answers and 15 views Find the range, mean, variance, and standard deviation of the population data set Find the range, mean, variance, and standard deviation of the population data set. 22, 14, 4, 6, 10 Asked 13 days ago by MelS 1 answers and 16 views Newton's laws A ball falls straight down through the air under the influence of gravity. There is a retarding force (air resistance) on the ball given by$F=bv$, where$v$is the speed of the ball and$b\$ is some constant greater than zero.  What is the magnitude of the acceleration of the ball at any time.

Asked 13 days ago by LanceJ

Kinematics

A basketball player 2.0 m tall want to make a basket from a distance of 9.0 m.  The hoop is at a height of 3.0 m.  If he shoot the ball (from a height of 2.0 m) at a 30o angle, at what initial speed must he throw the basketball so that it goes through the hoop without striking the backboard? ...

Asked 13 days ago by LanceJ

Circular Motion

This is a multipart question An air puck of mass 0.1 kg is tied to a string and allowed to revolve in a circle of radius 1 m on a horizontal, frictionless table.  The other end of the string passes through a hole in the center of the table and a mass of 0.5 kg is tied to it.  The suspended...

Asked 13 days ago by LanceJ

Conservation of Momentum

**1.** A revolutionary war cannon, with a mass of 2000 kg, fires a 15 kg ball horizontally.  The cannonball has a speed of 120 m/s after it has left the barrel.  The cannon carriage is on a flat platform and is free to roll horizontally.  What is the speed of the cannon immediately after it was...

Asked 13 days ago by LanceJ

A machine gun fires 50 g bullets at a speed of 700 m/s.

A machine gun fires 50 g bullets at a speed of 700 m/s.  The gun fires 130 bullets/min.  What is the average force the shooter must exert to keep the gun from moving?

Asked 13 days ago by LanceJ