Which of the following is the work done by the gravitational force on the object of mass 50 kg when the object is moved from one point to another point along a horizontal line (g = 10 m/s²)?
Zero
The work done by a force is defined as the dot product of the force and the displacement vector: \(W = \vec{F} \cdot \vec{d} = Fd\cos\theta\), where \(F\) is the magnitude of the force, \(d\) is the magnitude of the displacement, and \(\theta\) is the angle between the force and displacement vectors.
In this case, the gravitational force acts vertically downwards (towards the center of the Earth), while the object is moved along a horizontal line. Therefore, the angle between the gravitational force and the displacement vector is 90 degrees (\(\theta = 90^\circ\)).
Since \(\cos(90^\circ) = 0\), the work done by the gravitational force is:
\(W = Fd\cos(90^\circ) = Fd(0) = 0\)
The mass of the object (50 kg) and the acceleration due to gravity (g = 10 m/s²) are irrelevant because the gravitational force is perpendicular to the displacement. Regardless of the distance moved horizontally, no work is done by gravity.
Therefore, the correct answer is Zero.
Similar Questions
- The work done by a 10 Newton force acting on a body, which results in the displacement of 2 m in the direction of the force, is __________.
- An object of mass 1 kg is moving with a velocity 10 m/s. Find the kinetic energy of the object.
- The efficiency of a machine can never be ______.
- In practice, the work output of a machine is ______ the work input due to the effect of friction.
- How much energy is used by an 80% efficient, 2kW motor running at a peak load for 5 hours?
- A pump is required to lift 600 kg of water per minute from a well 25m deep and to eject it with a speed of 50 m/s. If \(g = 10 \text{ m/s}^2\), the power required to perform the above task is
- A lorry and a car moving with the same kinetic energy are brought to rest by applying the same retarding force. Then:
- In practice, the work output of a machine is always less than the work input due to the effect of ______.
- Ideal machines are those imaginary machines which are ______.
- The efficiency of a simple machine is defined as ______.
Important Questions from Work Power and Energy
Which of the following is an example of potential energy?
_______ is one of the chemical used to produce Ocean Thermal Energy.
A body of mass 2kg is thrown up vertically with a kinetic energy of 500J. If the acceleration due to gravity is 10 m/s2, the height at which the kinetic energy of the body becomes half of the original values is _____
Arjun has a mass of 50 kg, he eats banana of 1000 calories. If this energy is used up to lift him from the ground, the height to which he can climb is _______. Take g = 10 m/s2 and 1 calories = 4.2 Joule.
When a body of mass 'm' attains a velocity 'v' from rest in time 't', then kinetic energy of translation is:
