Recent questions in Work, Power and Energy

A cable that weighs 1.5 kg/meter and is attached to a bucket that weighs 75 kg. Initially, there are 500 kg of grain in the bucket and as the bucket is raised 2 kg of grain leaks out of a hole in the bucket for every meter the bucket is raised. The bucket is 200 meters below a bridge. How much work is required to raise the bucket to the top of the bridge?

asked Dec 13, 2015 by afiani.09

1 answer

A spring whose natural length is 15 cm exerts a force of 45 N when stretched to a length of 20 cm.Find the work done in stretching the spring from a length of 20 cm to a length of 25 cm

asked Sep 2, 2014 by sreemathi.v

1 answer

A force of 1200 N compresses a spring from its natural length of 18 cm to a length of 16 cm. How much work is done in compressing it from 16 cm to 14 cm?

asked Sep 2, 2014 by sreemathi.v

1 answer

A spring is stretched 60 cm, and it takes a force of 40 Newtons to hold it there. How much work did it take to stretch the spring to this point?

asked Sep 2, 2014 by sreemathi.v

1 answer

A wall is tilted in by $15^{\large\circ}$,and a 2kg block is placed against the wall.The block is held in place with a spring.The coefficients of friction between the block and the wall are $\mu_s=0.61$ and $\mu_k=0.49$.Holding the block in place requires that the spring be compressed by 12cm.What is the spring constant of the spring?

asked Sep 2, 2014 by sreemathi.v

1 answer

It takes 100J of work to stretch a spring 0.5m from its equilibrium position.How much work is needed to stretch it an additional 0.75m?

asked Sep 2, 2014 by sreemathi.v

1 answer

A force of 6 N is required to stretch a string from a natural length of 4 m to a length of 4.5 m.What work is required to stretch it to a length of 6 m.

asked Sep 2, 2014 by sreemathi.v

1 answer

Suppose 2 J of work is needed to stretch a spring from its natural length of 30 cm to a length of 42 cm.Then how far beyond its natural length will a force of 30 N keep the spring stretched?

asked Sep 2, 2014 by sreemathi.v

1 answer

Suppose 2 J of work is needed to stretch a spring from its natural length of 30 cm to a length of 42 cm.Then how much work is needed to stretch it from 30 cm to 40 cm.

asked Sep 2, 2014 by sreemathi.v

1 answer

A spring has a length of 15.4 cm and is hanging vertically from a support point above it.A weight with a mass of 0.200 kg is attached to the spring,causing it to extend to a length of 28.6cm.What is the value of the spring constant?

asked Sep 1, 2014 by sreemathi.v

1 answer

A spring has a natural length of 18 inches and a force of 20 lbs is required to stretch and hold the spring to a length of 24 inches. What is the work required in ft-lbs to stretch the spring from a length of 21 inches to a length of 26 inches?

asked Sep 1, 2014 by sreemathi.v

1 answer

A spring has a natural length of 1 meter.A force of 25 Newtons stretches the spring by $\large\frac{1}{4}$ of a meter.Determine how much work is done by stretching the spring from a length of 1.5 meters to 2.5 meters.

asked Sep 1, 2014 by sreemathi.v

1 answer

A spring has natural length 30 cm,and a force of 50 Newtons(N) is required to extend it to 35 cm.How much work is required to extend it from 32 to 36 cm?

asked Sep 1, 2014 by sreemathi.v

1 answer

A spring has a natural length of 20 cm. A 40 N force is required to stretch (and hold the spring) to a length of 30 cm. How much work is done in stretching the spring from 35 cm to 38 cm?

asked Sep 1, 2014 by sreemathi.v

1 answer

A block whose mass $m$ is $15\; kg$ slides on a horizontal frictionless surface with a constant speed $v$ of $3.7m/s$.It is brought momentarily to rest as it compresses a spring in its path.By what distance $d$ is the spring compressed?The spring constant $k$ is $1500\;N/m$

asked Sep 1, 2014 by sreemathi.v

1 answer

A spring has a natural length of 14 meters.If a force of 5N is required to keep the spring stretched 2 meters.How much work is done in stretching the spring from its natural length to a length of 18 meters.

asked Sep 1, 2014 by sreemathi.v

1 answer

A gas in a piston cylinder assembly undergoes an expansion process where $PV^{1.5}$=constant.The initial pressure is 3 bar,the initial volume is $0.1m^3$ and the final volume is $0.2m^3$.Determine the work done for this process.

asked Sep 1, 2014 by sreemathi.v

1 answer

We have a cable that weighs 2lbs/ft attached to a bucket filled with coal that weighs 800lbs.The bucket is initially at the bottom of a 500 ft mine shaft.Determine the amount of work required to lift the bucket to the midpoint of the shaft.

asked Sep 1, 2014 by sreemathi.v

1 answer

A particle of mass 0.5 kg moves on the positive $x$-axis under the action of a variable force $\large\frac{40}{x^2}$ newtons,directed away from origin..The particle passes through a point 2 metres from origin,with velocity $8ms^{-1}$ away from origin. Its experiences a constant resistance force of 6 newtons. Find the speed of the particle when it is 5 metres from origin.

asked Sep 1, 2014 by sreemathi.v

1 answer

Find the work done by F as it moves from a to b.

asked Sep 1, 2014 by sreemathi.v

1 answer

A 106g bullet is fired from a rifle having a barrel 0.441m long.Assuming the origin is placed where the bullet begins to move,the force exerted on the bullet by the expanding gas is $F=a+bx-cx^2$,where $a=13500N,b=8170N/m,c=24000N/m^2$,with $x$ in meters.With what velocity does the bullet exit the barrel?

asked Sep 1, 2014 by sreemathi.v

1 answer

A 106g bullet is fired from a rifle having a barrel 0.271m long.Assuming the origin is placed where the bullet begins to move,the force exerted on the bullet by the expanding gas is F=a+bx-cx$^2$,where a=13500N, b=8170N/m,c=24000N/m$^2$,with x in meters.Determine the work done by the gas on the bullet as the bullet travels the length of the barrel.

asked Sep 1, 2014 by sreemathi.v

1 answer

Force $F=(3x^2N)i+(4N)j$ acts on a particle changing only the kinetic energy of the particle.How much work is done on the particle as it moves from coordinates (2m,3m) to (3m,0m)?

asked Sep 1, 2014 by sreemathi.v

1 answer

What work is done by a force $F=(2xN)i+(3N)j$,with $x$ in meters,that moves a particle from a position $r_i=(2m)i+(3m)j$ to a position $r_f=-(4m)i-(3m)j$?

asked Sep 1, 2014 by sreemathi.v

1 answer

A particle moves along the $x$-axis from $x=0$ to $x=1$ under the influence of the force $F=(1+x^2)^{-1}$.Find the work done by this force.

asked Sep 1, 2014 by sreemathi.v

1 answer

A force $F_x$ acts on a particle.The force is related to the position of the particle by the formula $F_x=Cx^3$,where $C$ is a constant.Find the work done by this force on the particle when the particle moves from $x=1.5\;m$ to $x=3\;m$.

asked Sep 1, 2014 by sreemathi.v

1 answer