A person carries a mass of 10 kg and walks along the +x-axis for a distance of 100m with a constant velocity of 2 m/s. What is t
2 answers:
Answer:
Work done, W = 0
Explanation:
It is given that,
Mass of the object, m = 10 kg
Distance covered by the person, d = 100 m
Speed of the person, v = 2 m/s
We need to find the work done by this person. We know that the product of force and distance is equal to the work done by the person. Mathematically,
Since, the acceleration is equal to the rate of change of velocity. Here, the person is moving the mass with a constant velocity. So, there is no change in velocity, a = 0
As a result, the work done by the person is 0 J. So, the correct option is (c). Hence, this is the required solution.
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Answer
given,
before collision
mass of car A = m_a = 1300 kg
velocity of car A = v_a = 35 mph
mass of car B = m_b= 1000 kg
velocity of car B = v_b = 25 mph
after collision
V_a = 30 mph
V_b = 31.5 mph
Initial momentum
final momentum
here initial momentum is equal to the final momentum of the car.
hence, momentum is conserved in the collision.
Answer:
(a): The magnitude of the electric force on the small sphere =
(b): Shown below.
Explanation:
<u>Given:</u>
- m = mass of the small sphere.
- q = charge on the small sphere.
- L = length of the silk fiber.
= surface charge density of the large vertical insulating sheet.
When the dimensions of the sheet is much larger than the distance between the charge and the sheet, then, according to Gauss' law of electrostatics, the electric field experienced by the particle due to the sheet is given as:
<em>where,</em>
is the electrical permittivity of the free space.
The electric field at a point is defined as the amount of electric force experienced by a unit positive test charge, placed at that point. The magnitude electric field at a point and the magnitude of the electric force on a charge q placed at that point are related as:
Thus, the magnitude of the electric force on the small sphere is given by
The sheet and the small sphere both are positively charged, therefore, the electric force between these two is repulsive, which means, the direction of the electric force on the sphere is away from the sheet along the line which is perepndicular to the sheet and joining the sphere.
<h2>(b):</h2>
When the sphere is in equilibrium, the tension in the fiber is given by the resultant of the weight of the sphere and the electric force experienced by it as shown in the figure attached below.
According to the fig.,
<em>where,</em>
= electric force on the sphere, acting along left.
= weight of the sphere, acting vertically downwards.
<em />
g is the acceleration due to gravity.
