Which requires more work- lifting a 50-kg sack a vertical distance of 2 m or lifting a 25-kg sack a vertical distance or 4 m? Both are the same amount of work because the force x distance is the same for each.
Can a machine multiply input force input distance input energy?
A machine can multiply force and it can multiply distance. However, it cannot multiply input energy because this would violate the law of conservation of energy.
When the speed of a moving car is doubled How much more kinetic energy does it have?
This means that when the velocity of an object doubles, its kinetic energy quadruples. A car traveling at 60 mph has four times the kinetic energy of an identical car traveling at 30 mph, and hence the potential for four times more death and destruction in the event of a crash.
What is the efficiency of a machine that miraculously converts all the input energy to useful output energy?
The efficiency of this machine is 1, or 100%. Based on thermodynamic arguments, it is generally said that such a perfect machine is impossible to construct.
Which requires more work lifting a 50 kg sack at 2.0 m or lifting a 25 kg sack at vertical distance of 4.0 m?
Which requires more work: lifting a 50-kg sack a vertical distance of 2 m or lifting a 25-kg sack a vertical distance of 4 m? Both take the same 1000 J.
What is Ke formula?
Kinetic energy is directly proportional to the mass of the object and to the square of its velocity: K.E. = 1/2 m v2. If the mass has units of kilograms and the velocity of meters per second, the kinetic energy has units of kilograms-meters squared per second squared.
Can a machine increase both force and distance?
A machine is any device that makes work easier by changing a force. Machines may increase the strength of the force, increase the distance over which the force is applied, or change the direction in which the force is applied.
What 2 ways can a machine alter an input force?
A machine can alter an input force by changing its (1) magnitude, or (2) direction. All machines are subject to energy conservation in that no machine can output more energy (do more work) than the energy put into it.
Is kinetic energy zero when the object is not moving?
If it is not in motion, the kinetic energy of that object is zero. Kinetic energy can never be a negative value. Kinetic energy can be quantified as one half of the mass times the velocity squared (KE = 1/2*m*v²). In SI units, the mass should be in kilograms (kg), and the velocity in meters per second (m/s).
What factor affect the kinetic energy?
Explain that there are two factors that affect how much kinetic energy a moving object will have: mass and speed.
Is kinetic energy can be negative?
The kinetic energy of a body cannot be negative because the mass cannot be negative and the square of the speed gives a non-negative number. However, the change in kinetic energy can be negative. Was this answer helpful?
What is the relationship between speed and kinetic energy?
From this formula, we can observe that the kinetic energy of an object is directly proportional to the square of its speed. This means that the speed doubles and kinetic energy increases by a factor of four. If the speed increases by a threefold, the kinetic energy will increase by a factor of nine.
Why are machines not 100 efficient?
Machine Efficiency Efficiency is the percent of work put into a machine by the user (input work) that becomes work done by the machine (output work). The output work is always less than the input work because some of the input work is used to overcome friction. Therefore, efficiency is always less than 100 percent.
When we say a machine runs at 40 efficiency This means that?
The meaning of the statement ” An efficiency of the engine is 40 percent ” is that only 40 percent of input energy is utilised to do output work. The ratio of output and input energy is 0.4.
What is the correct formula for efficiency?
Efficiency can be expressed as a ratio by using the following formula: Output ÷ Input. Output, or work output, is the total amount of useful work completed without accounting for any waste and spoilage. You can also express efficiency as a percentage by multiplying the ratio by 100.
Which requires more work lifting a 70 kg sack?
1 Answer. Both require the same amount if work.
Which job requires more work lifting a 70 kg sack vertically 2 meters or lifting a 35 kg sack vertically 4 meters?
The energy consumption will be more in the lifting of 70 kg as compared to the lifting of 35 kg. Hence, work done on a heavier object for the same distance will be more as compared to the lighter one.
Which if either requires more work lifting a 10 kg load a vertical distance of 2 m or lifting a 5 kg load a vertical distance of 4 m?
Which requires more work, lifting a 10-kg load a vertical distance of 2 m or lifting a 5-kg load a vertical distance of 4 m? They are the same.
What are 4 types of kinetic energy?
- Mechanical Energy. Mechanical energy is the energy that we can see.
- Electrical Energy. Electrical energy is better known as electricity.
- Light Energy (or Radiant Energy)
- Thermal Energy.
- Sound Energy.
What is the S.I unit of kinetic energy?
S.I unit of kinetic energy is joule(J).
Is velocity a speed?
Speed is the time rate at which an object is moving along a path, while velocity is the rate and direction of an object’s movement. Put another way, speed is a scalar value, while velocity is a vector.
What is effort formula?
To calculate the effort required by the load, we divide the load by the number of ropes. If the person pulls a load of 500 kg using a five rope pulley system, he experiences a pull that is equal to 100 kg only. We calculate the effort force of pulley in the above example, we do the following: 500 kg/4 = 100 kg.
What is the SI unit for work?
Scientists use the joule to measure work. One joule is equal to the work done by a force of one newton to move an object one meter in the direction of the force.
Can simple machine multiply energy?
Machines simply transmit mechanical work from one part of a device to another part. A machine produces force and controls the direction and the motion of force, but it cannot create energy. A machine’s ability to do work is measured by two factors. These are (1) mechanical advantage and (2) efficiency.
Is work a form of energy?
a. TRUE – Work is a form of energy, and in fact it has units of energy.