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. Помогите пожалуйста с решением. С вашего позволения задам несколько вопросов в комментариях.

Answer 1

По второму закону Ньютона F=dp/dt
dp=m*V0-m*V При упругом ударе V=-V0
dp=m*V0-(-m*V0)=2*m*V0
F=2*m*V0/dt=2*0,1*10/10^-3=2*10^3 H
a=F/m=2*10^3/0,1=2*10^4 м/с2

Answer 2

Problem Analysis

We are given the following information: - Mass of the ball, m = 100 g - Initial velocity of the ball, v0 = 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.

Solution

To solve this problem, we can use the principles of conservation of momentum and Newton's second law of motion.

# Step 1: Convert mass to kilograms

The mass of the ball is given in grams, so we need to convert it to kilograms. We know that 1 kg = 1000 g, so the mass of the ball in kilograms is:

m = 100 g = 100/1000 kg = 0.1 kg

# Step 2: Calculate the change in velocity

Since the ball rebounds from the wall with the same magnitude of velocity, the change in velocity is given by:

Δv = 2 * v0

Substituting the given value of v0:

Δv = 2 * 10 m/s = 20 m/s

# Step 3: Calculate the time of contact

The ball is in contact with the wall for 1 ms, which is equivalent to 0.001 s.

t = 0.001 s

# Step 4: Calculate the acceleration

Using Newton's second law of motion, we can calculate the acceleration of the ball during the contact with the wall:

F = m * a

where F is the average braking force and a is the acceleration.

Since the ball is in contact with the wall for a very short time, we can assume that the average braking force is constant during this time. Therefore, we can rewrite Newton's second law as:

F * t = m * Δv

Solving for acceleration:

a = (m * Δv) / (F * t)

# Step 5: Calculate the average braking force

To calculate the average braking force, we rearrange the equation from step 4:

F = (m * Δv) / (a * t)

Substituting the known values:

F = (0.1 kg * 20 m/s) / (a * 0.001 s)

Now we have the equations to calculate the acceleration and the average braking force.

Calculation

Let's calculate the acceleration and the average braking force using the given values.

# Calculation of acceleration:

a = (m * Δv) / (F * t)

Substituting the known values: a = (0.1 kg * 20 m/s) / (F * 0.001 s)

# Calculation of average braking force:

F = (m * Δv) / (a * t)

Substituting the known values: F = (0.1 kg * 20 m/s) / (a * 0.001 s)

Answer

The acceleration of the ball during the contact with the wall is . The average braking force acting on the ball is .

Please note that the actual values for acceleration and average braking force cannot be determined without additional information. The equations provided above are the general formulas to calculate these quantities.