Graphite powder is used in machines to_______

When the height of the inclined plane decreases :

When the height of the inclined plane decreases :

For an ideal machine:

Mechanical advantage of a lever is

Wedge is a :

Efficiency of machine is

Relationship between the mechanical advantage and velocity ratio of an ideal machine is

Relationship between mechanical advantage and velocity ratio for a practical machine is

The ratio of the load to the effort is called.

Ratio of velocity of effort to the velocity of load is called.

It is difficult to climb the steps having greater inclination. Why?

Velocity Ratio of a machine is more than 1. It 

A force of 10N raised a load of 400 kg. Calculate mechanical advantage of the machine.

A machine is used to displace a load of $200$ N through $5$ cm by an effort of $10$ N. If efficiency of the machine is $50\%$. Find its mechanical equivalent.

A pulley system of VR of 2 and efficiency of 50%. If the effort moves through a distance of 5m. Calculate the distance moved by the load.

........ is defined as the ratio of the distance moved by effort and load, in the same time interval.

Efficiency is

A machine in which displacement of load is more than the displacement of effort, will have the velocity ratio

Friction has no effect on 

Effeciency of inclined plane

Mechanical advantage of an inclined plane is 

Akhil has to lift a load of $800N$ onto a platform of $2m$ height. Instead, he pushes the load up a ramp $4m$ long. Find the force required to lift the load vertically up.

Mechanical advantage =________.

Which of the following statements is NOT correct?

Mechanical advantage of wheel and axle is: ($R=$ radius of the wheel, $r$ = radius of the axle)

The ratio of the work output to the work input of a machine is

Which of the following is not considered a simple machine?

A screwdriver can be used to open a can of paint. In this situation, the screwdriver is being used as a

The ratio of distance travelled by the effort to the distance travelled by the load in the machine is called-

An oar is used to row a boat. The distance between the oar lock (fulcrum) and the rower's hand is $104 cm$. This distance is considered

The mechanical advantage of each machine is determined by

The mechanical advantage of another oar is $3.00$. If the resistance force of the water is $35.0\ lb$, what is the effort force exerted by the rower?

In a lifting machine, an effort of $500$ N is to be moved by a distance of $20$ m to raise a load of $10000$ N by a distance of $0.8$ m. Determine the velocity ratio and mechanical advantage?

In an ideal machine,

What load will be lifted by an effort of $12$ $N$ if the velocity ratio is $18$ and the efficiency of the machine at this load is 60%?

In a lifting machine, the efforts required for lifting loads of $20$ N and $30$ N were $5$ N and $6$ N respectively. If the velocity ratio of the machine is $20$, determine efficiencies corresponding to loads of $20 $ N and $30$ N

The mechanical advantage for a pulley system is determined by

If a machine overcomes a load $L$ and the distance travelled by the load is $L _d$. Similarly, the effort applied in the machine is $E$ and the distance travelled by effort is $E _d$, and $'T'$ is the time taken then velocity ratio can be written as 

In a lifting machine, an effort of 500 N is to be moved by a distance of 20 m to raise a load of 10,000 N by a distance of 0.8 m. Determine the velocity ratio and mechanical advantage.

Fill in the blank.
In second order lever, velocity ratio 

In a lifting machine, an effort of 500 N is to be moved by a distance of 20 m to raise a load of 10,000 N by a distance of 0.8 m. Determine the effort lost in friction

Efficiency of a machine can also be written as 

Fill in the blank.
In the first order of lever, velocity ratio is usually __than 1 but could be __ or equal to 1

You do 1200 J of work with gears. If the gears do 1000 J of work, what is the efficiency of the gears?

You do 1260 J of work with a wheel and axle. If the wheel and axle does 1200 J of work, what is the efficiency of the wheel and axle?

It is easier to draw up a wooden block along an inclined plane than to haul it vertically, principally because:

A pump ejects $12000\ kg$ of water at the speed of $4\ { m }/{ s }$ in $40\ second.$ Find the average rate at which the pump is working

The mechanical advantage of inclined plane of angle of inclination $60^{\circ}$ is equal to :

Mechanical advantage is equal to 

Akhil has to lift a load of 800 N onto a platform of 2 m height. Instead, he pushes the load up a ramp 4 m long. Find the force required to roll the load up the ramp.

The ratio of the radius of two wheels A and B are in the ratio 3 : 7 respectively and the ratio of their respective axles is 5 : 4. Identify the wheel and axle that has greater mechanical advantage?

In a wheel-axle arrangement, the radius of wheel is 25 times more than the radius of an axle. Find the mechanical advantage of the machine.

Which of the following statements in NOT correct?

An effort of 20 kgf is applied on a machine through a distance of 80 cm, when a load of 30 kgf moves through a distance of 1 cm. Calculate the velocity ratio of the machine.

Akhil has to lift a load of 800 N onto a platform of 2 m height. Instead, he pushes the load up a ramp 4 m long. Find the work done by Akhil in lifting the load vertically up.

A crow-bar of length $2.0$ m is used as a machine to lift a box of $100$ kgf by placing a fulcrum at a distance of $0.1$ m from the box. Calculate the effort required.

A nut can be opened by a lever of length $0.25$ m by applying a force of $80$ N. What should be the length of the lever if a force of $32$ N is enough to open the nut?

A rubber ball dropped from a height of $20\ m (g = 10\ m/s^{2})$ falls on the roof of an elevator going up at $2\ m/s$. If the collision of the ball with the elevator is elastic, the ball rebounds with a velocity of

Efficiency of engine is $\eta _1$ at $T _1 = 200^\circ C$ and $T _2 = 0^\circ C$ and $\eta _2$ at $T _1 = 0^\circ C$ and $T _2 = -200 K$. Find the ratio of $\dfrac{\eta _1}{\eta _2}$.

A man of mass $80kg$ carrying a load of $20kg$ walks up a stair case in $20s$. If the number of steps is $40$ and width and height of each step are $20cm$ and $15cm$ respectively. The efficiency of the man is

A man uses a crowbar of length $1.5m$ to raise a load of $75kgf$ by putting a sharp edge below the bar at a distance $1m$ from his hand. Calculate the mechanical advantage. 

A water -pump driven by petrol raises water at a rate $ 0.5 m^3/min $ from a depth of 30 m. if the pump is 70% efficient, what power is developed by the engine?

A $20\ N$ metal block is suspended by a spring balance. A beaker containing some water is placed on a weighing machine which reads $40\ N$. The spring balance is now lowered so that the block gets immersed in the water. The spring balance now reads $16\ N$. The reading of the weighing machine will be 

A man uses a crowbar of length $1.5m$ to raise a load of $75kgf$ by putting a sharp edge below the bar at a distance $1m$ from his hand. Calculate the effort needed.

A boy can exert a maximum effort of $250\  N$, so he uses an inclined plane to lift the load up. What should be the minimum length of the plank used by him to lift a mass of $ 50 \ kg$ to a height of $1 \ m$ ?

A coolie uses a sloping wooden plank of length $2.0 m$ to push up a drum of mass $100 kg$ into the truck at a height $1.0 m$. What is the mechanical advantage of the sloping plank ?

A fire tongs has its arms $20cm$ long. It is used to lift a coal of weight $1.5kgf$ by applying an effort at a distance $15cm$ from the fulcrum. Find the mechanical advantage of fire tongs.

A fire tongs has its arms $20 \ cm$ long. It is used to lift a coal of weight $1.5 \ kgf$ by applying an effort at a distance $15 \ cm$ from the fulcrum. Find the effort needed.

It is harder to cut an apple with a butter-knife, because:

It is difficult to climb the steps having greater inclination. Why?

For a _________, the mechanical advantage is always less than one.

Mechanical advantage of a second order lever is :

If the threads of a screw are closer : 

The force applied on the machine to overcome the load is called

The resistive or opposing force to be overcome by a machine is called the

When the same amount of force is applied :

A boy can exert a maximum force of $10$kg, i.e he cannot lift vertically a load of mass more than $10$kg. Now if he wants to raise a load of mass $20$kg on to a high eall, he can do it with the help of an inclined place making an angle $\theta$ with the horizontal. Find $\theta$.

The velocity ratio of a machine is 1 if 

As the closeness of threading increases in a screw :

It is harder to cut an apple with a butter knife, because :

If a machine overcomes a load $L$ and the distance travelled by the load is $25 m$. Similarly, the effort applied in the machine is $E$ and the distance travelled by effort is $75 m$, and $'T'$ is the time taken,then velocity ratio is:

A load will be lifted by an effort of 12 N, the velocity ratio is 18 and the efficiency of the machine at this load is 60%, if the machine has a constant frictional resistance, determine the law of machine.

In a simple machine, whose velocity ratio is $30$, a load of $2400$ N is lifted by an effort of $150$ N and a load of $3000$ N is lifted by an effort of $180$ N. Find the law of machine -

In a simple machine, whose velocity ratio is $30$, a load of $2400 N$ is lifted by an effort of $150$ N and a load of $3000$ N is lifted by an effort of $180$ N. Calculate the amount of effort wasted in overcoming the friction using a force of $200 N$. 

A machine gun is mounted on a 2000 kg car on a horizontal frictionless surface. At some instant, the gun fires 10 bullets/second, each of mass 10 g with a velocity of 500 m s$^{-1}$. The acceleration of the car is