Question

Мяч массой 100 г, брошенный перпендикулярно стене со скоростью 10 м/с, отскакивает от нее с той же по модулю скоростью. Определите ускорение и среднюю силу торможения мяча, если мяч находился в контакте со стеной в течение 1 мс.

Answer 1

F=dp/dt=2*m*V/dt=2*0,1*10/10^-3=2000 Н
a=F/m=2000/0,1=2*10^4 м/с2

Answer 2

Problem Analysis

We are given the following information: - The mass of the ball is 100 g. - The ball is thrown perpendicular to a wall with a velocity of 10 m/s. - The ball rebounds from the wall with the same magnitude of velocity. - The ball is in contact with the wall for 1 ms.

We need to determine the acceleration and the average braking force acting on the ball during contact with the wall.

Solution

To solve this problem, we can use the principles of conservation of momentum and impulse-momentum.

# Step 1: Convert the mass of the ball to kilograms.

The mass of the ball is given as 100 g. To convert it to kilograms, we divide by 1000: - Mass of the ball (m) = 100 g = 0.1 kg.

# Step 2: Calculate the change in velocity.

The ball is thrown perpendicular to the wall with a velocity of 10 m/s. It rebounds from the wall with the same magnitude of velocity. Therefore, the change in velocity is: - Change in velocity (Δv) = 10 m/s - (-10 m/s) = 20 m/s.

# Step 3: Calculate the time of contact.

The ball is in contact with the wall for 1 ms. To use this value in our calculations, we need to convert it to seconds: - Time of contact (Δt) = 1 ms = 0.001 s.

# Step 4: Calculate the acceleration.

Using the equation for acceleration, we can calculate the acceleration of the ball during contact with the wall: - Acceleration (a) = Δv / Δt = 20 m/s / 0.001 s = 20,000 m/s^2.

# Step 5: Calculate the average braking force.

Using the equation for average force, we can calculate the average braking force acting on the ball during contact with the wall: - Average force (F) = m * a = 0.1 kg * 20,000 m/s^2 = 2,000 N.

Answer

Therefore, the acceleration of the ball during contact with the wall is 20,000 m/s^2, and the average braking force acting on the ball is 2,000 N.