Question

ПОМОГИТЕ ПОЖАЛУЙСТА))))1)Брусок прижат к вертикальной поверхности рукой .Изобразите силы действующие на брусок когда он движется с ускорение вниз.2)Определите массу автомобиля,разгоняющегося с ускорение 1.5 м\с^2 на горизонтальной дороге под действием силы тяги 15 кН. Сила трения равна 6кН

Answer 1

1)
Сила тяжести - вниз!
Сила трения - противоположно движению!
Сила руки - вниз!

Answer 2

Forces Acting on a Block Pressed Against a Vertical Surface

When a block is pressed against a vertical surface and is moving downward with acceleration, several forces act on it. The forces can be represented as follows:

1. Weight (W): The force exerted by the Earth on the block due to gravity. It acts vertically downward and can be calculated using the formula W = mg, where m is the mass of the block and g is the acceleration due to gravity (approximately 9.8 m/s^2). 2. Normal Force (N): The force exerted by the vertical surface on the block perpendicular to the surface. It acts vertically upward and is equal in magnitude and opposite in direction to the weight of the block. The normal force prevents the block from sinking into the surface. 3. Frictional Force (F): The force exerted by the surface on the block parallel to the surface. It acts in the opposite direction to the motion of the block and opposes its movement. The frictional force can be further divided into static friction (when the block is at rest) and kinetic friction (when the block is in motion).

Please note that the direction of the forces mentioned above is based on the assumption that the block is moving downward. If the block is moving upward, the direction of the forces would be reversed.

Determining the Mass of an Accelerating Car

To determine the mass of an accelerating car, we can use Newton's second law of motion, which states that the net force acting on an object is equal to the product of its mass and acceleration (F = ma).

In this case, the net force acting on the car is the difference between the force of traction (the force that propels the car forward) and the force of friction. The force of traction is given as 15 kN, and the force of friction is given as 6 kN.

Using the formula F = ma, we can rearrange it to solve for mass (m):

F = ma 15 kN - 6 kN = m * 1.5 m/s^2 9 kN = m * 1.5 m/s^2 m = (9 kN) / (1.5 m/s^2)

To calculate the mass, we need to convert the forces from kilonewtons (kN) to newtons (N) and the acceleration from meters per second squared (m/s^2) to meters per second (m/s). 1 kN is equal to 1000 N.

m = (9 kN * 1000 N/kN) / (1.5 m/s^2) m = 6000 kg

Therefore, the mass of the car is 6000 kg.

Please let me know if there's anything else I can help you with!