A player strikes a hockey puck giving it a velocity of 47.673 m/s. The puck slides across the ice for 0.175 s after which time its velocity is 46.473 m/s.
The acceleration of gravity is 9.8 m/s2 . The mass of the puck is 185 g.
If the puck strikes the goalie’s pads and stops
in a distance of 4.39 cm, what average force is
exerted on the pads?
Answer in units of N.
I wonder what the velocity of the puck was at the initial contact with the pad? If you assume it is 46.473m/s, then
46.473^2=2(force/masspuck)*.0439
and you solve for force (mass is in kg)
To find the average force exerted on the goalie's pads, we can use the impulse-momentum principle. The impulse experienced by an object is equal to the change in its momentum. The impulse can be calculated as the product of the average force and the time interval over which the force is applied.
The initial momentum of the puck can be calculated using its mass and initial velocity:
Initial momentum = mass * initial velocity
Then, the final momentum of the puck can be calculated using its mass and final velocity:
Final momentum = mass * final velocity
The change in momentum can be calculated by subtracting the initial momentum from the final momentum:
Change in momentum = Final momentum - Initial momentum
Now, using the equation for impulse:
Impulse = Change in momentum
Since impulse is equal to the average force multiplied by the time interval, we can rearrange the equation to solve for average force:
Average force = Impulse / Time interval
First, we need to convert the mass of the puck from grams to kilograms:
Mass = 185 g / 1000 = 0.185 kg
Next, we can calculate the initial momentum:
Initial momentum = 0.185 kg * 47.673 m/s
Then, we calculate the final momentum:
Final momentum = 0.185 kg * 46.473 m/s
Now, we can calculate the change in momentum:
Change in momentum = Final momentum - Initial momentum
Next, we need to convert the distance over which the puck stops from centimeters to meters:
Distance = 4.39 cm / 100 = 0.0439 m
Finally, we can calculate the time interval using the distance and the final velocity of the puck:
Time interval = Distance / Final velocity
Now, substitute the values into the equation for average force:
Average force = Change in momentum / Time interval
Calculate the average force using the calculated values.
Note: Since the question does not provide the values for initial and final velocities, the calculated average force may be inaccurate without that information.