How will the weight of a 20kg object change in an elevator if the elevator moves downwards with 4 m.s?
Moving at a constant speed changes nothing. All the laws of physics and forces are the same in a coordinate system moving at constant speed in a straight line. Einstein used that assumption to develop the Theory of Relativity
To determine how the weight of a 20kg object will change in an elevator moving downwards with a velocity of 4 m/s, you need to understand the concept of weight and the influence of motion on weight.
Weight is the force exerted by an object due to gravity. On Earth, weight is typically calculated as the mass of an object multiplied by the acceleration due to gravity (9.8 m/s^2).
When the elevator moves, it introduces an additional force acting on the object in addition to the force of gravity. This additional force is the acceleration or deceleration caused by the elevator's motion.
In this case, the elevator is moving downwards with a velocity of 4 m/s. Since the elevator is moving in the opposite direction to the force of gravity, it creates a net force that partially counteracts the force of gravity and thus reduces the apparent weight of the object.
To calculate the weight of the object in this scenario, you can use the formula:
Weight = Mass × (Acceleration due to gravity - Acceleration due to elevator's motion)
Let's plug in the values:
Mass = 20 kg
Acceleration due to gravity = 9.8 m/s^2 (constant on Earth)
Acceleration due to elevator's motion = 4 m/s (downwards)
Weight = 20 kg × (9.8 m/s^2 - 4 m/s)
Weight = 20 kg × 5.8 m/s^2
Weight = 116 N
Therefore, the weight of the 20kg object in the elevator moving downwards with a velocity of 4 m/s will be 116 Newtons (N).