Is the cart labor-saving, or pull the car effort?
From the point of view of human comfort, pulling a cart is more comfortable than a trolley, and pulling a car can make use of the human body's center of gravity to a certain extent.
From a physical point of view, the carts and carts need to do as much work.
Pulling a cart is more labor-saving than a cartThe cart is easy to use and can be pushed or pulled. Push and pull the direction of force with the same angle as the horizontal line, is the cart labor-saving or pull the car effort? Labor-saving and labor-saving, mainly depends on how much resistance the wheels are. The car is able to move forward because of overcoming resistance. In the same conditions of the ground, the greater the pressure on the ground, the greater the resistance, resistance is difficult. Conversely, the pressure is small, resistance is small, effort saving. The cart was hard in the direction pointing downward, it has two effects: a force forward, to overcome resistance, make the car move uniformly; another vertical component really downward, increased the pressure on the ground of the car, the resistance increased. When pulling the car, the direction of the force is pointing upwards, and it also produces two components. One is used to overcome the resistance, the other is vertical, which reduces the pressure on the ground and reduces the resistance. Therefore, when you pull the car, you need to overcome the small resistance, it will save effort
