Answer:
The centripetal force acting on the skater is <u>48.32 N.</u>
Explanation:
Given:
Radius of circular track is, 
Tangential speed of the skater is, 
Mass of the skater is, 
We are asked to find the centripetal force acting on the skater.
We know that, when an object is under circular motion, the force acting on the object is directly proportional to the mass and square of tangential speed and inversely proportional to the radius of the circular path. This force is called centripetal force.
Centripetal force acting on the skater is given as:

Now, plug in the given values of the known quantities and solve for centripetal force,
. This gives,

Therefore, the centripetal force acting on the skater is 48.32 N.
Complete Question
The complete question is shown on the first uploaded image
Answer:
The velocity is
in positive x -direction
The speed is 
Explanation:
From the question we are told that
The distance from the house to truck is D = 20 m
The distance traveled back to retrieve wind-blown hat is d = 15
The distance from the wind-blown hat position too the truck is k = 20 m
The total time taken is t = 75 s
Generally when calculating the displacement the Justin's backward movement to collect his wind - blown hat is taken as negative
Generally Justin's displacement is mathematically represented as

=> 
Generally the average velocity is mathematically represented as

=> 
=>
Generally the distance covered by Justin is mathematically represented as

=> 
=> 
Generally Justin's average speed over a 75 s period is mathematically represented as

=> 
=> 
Answer:
I = 2 kgm^2
Explanation:
In order to calculate the moment of inertia of the door, about the hinges, you use the following formula:
(1)
I: moment of inertia of the door
α: angular acceleration of the door = 2.00 rad/s^2
τ: torque exerted on the door
You can calculate the torque by using the information about the Force exerted on the door, and the distance to the hinges. You use the following formula:
(2)
F: force = 5.00 N
d: distance to the hinges = 0.800 m
You replace the equation (2) into the equation (1), and you solve for α:

Finally, you replace the values of all parameters in the previous equation for I:

The moment of inertia of the door around the hinges is 2 kgm^2
Answer:
B=
≅8.06
Explanation:
Using the Pythagorean theorem:
=
+ 
where C represents the length of the hypotenuse and A and B the lengths of the triangle's other two sides, we can find out the lenght of B assuming the value of the hypotenuse being 9 and A being 4.
=
+ 
81= 16+ 
81-16= 
B=
≅8.06
Answer:
2.08 kg
Explanation:
Newton's second law states that the acceleration of an object is proportional to the force applied to the object, according to the equation:

where F is the force applied, m is the mass of the object and a its acceleration.
In this situation, the soccer ball is kicked with a force F=13.5 N and its acceleration is a=6.5 m/s^2, therefore its mass is
