A 20.0 kg box rests on a table. what is the weight of the box and the normal force acting on it? A 10.0 kg box is set on top of the 20.0kg box. Determine the normal force that the table exerts on the 20.0kg box and the normal force that the 20.0kg box exerts on the 10.0kg box.
a. 20kg or 20*9.8 N is the weight, and the normal force.
b. The 10kg box exerts a normal force of 10*g on the lower box. THe lower box exerts this same force upward on the upper box.
4- A window washer pulls herself upward using the bucket–pulley apparatus shown in the Fig. (a) How hard must she pull downward to raise herself slowly at constant speed? (b) If she increases this force by 15%, what will her acceleration be? The mass of the person plus the bucket is 72 kg.
To find the weight of an object, you need to know its mass and the acceleration due to gravity. The weight of an object is equal to the mass of the object multiplied by the acceleration due to gravity.
In this case, the mass of the 20.0 kg box is given, so we can find its weight. The acceleration due to gravity is approximately 9.8 m/s² on the surface of the Earth.
Weight of the 20.0 kg box = mass × acceleration due to gravity
= 20.0 kg × 9.8 m/s²
= 196 Newtons (N)
The normal force is the force exerted by a surface to support the weight of an object resting on it. It acts perpendicular to the surface and prevents the object from sinking into or passing through the surface.
In this case, the normal force that the table exerts on the 20.0 kg box is equal in magnitude to the weight of the box, as long as the box is not accelerating vertically. Therefore, the normal force is also 196 N in this case.
Now, let's consider the second scenario where a 10.0 kg box is set on top of the 20.0 kg box. The 20.0 kg box now has an additional force acting on it due to the weight of the 10.0 kg box.
To find the normal force that the table exerts on the 20.0 kg box, we need to calculate the combined weight of both boxes and add the two weights together.
Weight of the combined boxes = Weight of the 20.0 kg box + Weight of the 10.0 kg box
= (20.0 kg × 9.8 m/s²) + (10.0 kg × 9.8 m/s²)
= 196 N + 98 N
= 294 N
Therefore, the normal force that the table exerts on the 20.0 kg box in this scenario is 294 N.
To find the normal force that the 20.0 kg box exerts on the 10.0 kg box, we use Newton's third law of motion, which states that for every action, there is an equal and opposite reaction. In this case, the normal force exerted by the 20.0 kg box on the 10.0 kg box is equal in magnitude to the normal force exerted by the 10.0 kg box on the 20.0 kg box, but in the opposite direction.
Therefore, the normal force that the 20.0 kg box exerts on the 10.0 kg box is also 294 N.