A man with a mass of 80KG stands on a bathroom scale on the floor of a lift. Determine the reading of the scale if the lift moves downwards with a constant velocity at 2metre per second.
constant velocity means NO ACCELERATION
therefore just the weight
80 * 9.81 = 785 Newtons
To determine the reading of the scale, we need to consider the forces acting on the man in the lift.
When the man is at rest or moving with a constant velocity, the net force acting on him must be zero according to Newton's first law of motion. In this case, the downward force due to gravity and the upward force exerted by the bathroom scale must be equal in magnitude and opposite in direction.
Since the lift is moving downwards at a constant velocity, the acceleration of the man is zero. Therefore, we can say that the man experiences equilibrium.
The weight of an object is given by the formula:
Weight = mass * acceleration due to gravity
In this case, the weight of the man is:
Weight = 80 kg * 9.8 m/s^2
Weight = 784 N
Since the man is at equilibrium, the reading on the scale would be equal to the weight of the man. Therefore, the reading on the scale would be 784 Newtons downward.