a 0.055kg tennis ball approaches a tennis racket at 25m/s, stays in contact with it for 0.010s, is reversed in direction leaves the racket at 40m/s. what is the avg force between the racket and ball?

a=(V-Vo)/t = (-40-25)/0.01=-6500 m/s^2.

F = m*a = 0.055 * -6500 = -358 N.

a 0.005 kg tennis ball approaches a racket at an initial velocity 25 m/s2 . if its is in contact with the racket's strings for 0.005 s, then rebounds at 45 m/s2 what is the average contact force between the ball and the racjet?

To find the average force between the racket and ball, we can use Newton's second law of motion, which states that the force acting on an object is equal to the rate of change of its momentum.

1. Calculate the initial momentum of the tennis ball:
Momentum (p) = mass (m) * velocity (v)
p = 0.055 kg * 25 m/s
p = 1.375 kg·m/s

2. Calculate the final momentum of the tennis ball:
Momentum (p) = mass (m) * velocity (v)
p = 0.055 kg * (-40 m/s)
p = -2.2 kg·m/s (negative sign indicates the reversal in direction)

3. Calculate the change in momentum:
Change in Momentum (Δp) = Final Momentum - Initial Momentum
Δp = -2.2 kg·m/s - 1.375 kg·m/s
Δp = -3.575 kg·m/s

4. Calculate the average force:
Average Force (F) = Change in Momentum / Time
F = Δp / Δt
F = -3.575 kg·m/s / 0.010 s
F = -357.5 N

The negative sign indicates that the force exerted by the racket on the ball is in the opposite direction of the ball's motion. Therefore, the average force between the racket and ball is 357.5 Newtons in the opposite direction to the motion of the ball.

To find the average force between the racket and the ball, you can use Newton's second law of motion, which states that the force acting on an object is equal to the rate of change of its momentum. The momentum of an object is defined as the product of its mass and velocity.

Before we can calculate the average force, we need to determine the initial and final momenta of the tennis ball.

Given:
Mass of the tennis ball (m) = 0.055 kg
Initial velocity of the tennis ball (v1) = 25 m/s
Final velocity of the tennis ball (v2) = -40 m/s (since it reverses in direction)

Step 1: Calculate the initial momentum (p1) of the tennis ball.
Initial momentum (p1) = mass (m) * initial velocity (v1)
p1 = 0.055 kg * 25 m/s
p1 = 1.375 kg⋅m/s

Step 2: Calculate the final momentum (p2) of the tennis ball.
Final momentum (p2) = mass (m) * final velocity (v2)
p2 = 0.055 kg * (-40 m/s)
p2 = -2.2 kg⋅m/s

Step 3: Calculate the change in momentum (Δp) of the tennis ball.
Change in momentum (Δp) = final momentum (p2) - initial momentum (p1)
Δp = -2.2 kg⋅m/s - 1.375 kg⋅m/s
Δp = -3.575 kg⋅m/s

Step 4: Calculate the average force (Favg) using Newton's second law.
Average force (Favg) = change in momentum (Δp) / time interval (Δt)
Given that the time interval (Δt) is 0.010 s,
Favg = -3.575 kg⋅m/s / 0.010 s
Favg = -357.5 N

The average force between the racket and the ball is -357.5 N. The negative sign indicates that the force is in the opposite direction of the initial velocity of the ball.