Forces and kinetic energy problem

In summary, the question asks for Shawn's kinetic energy based on his mass and velocity while riding his bike for a distance of 1.3 km in 10.4 minutes. After converting the units, the average velocity is calculated to be approximately 2.08333 m/s. Using the formula for kinetic energy, the answer is calculated to be 45.3124 J.
  • #1
kza62
14
0

Homework Statement


Shawn and his bike have a total mass of 43.5 kg. Shawn rides his bike 1.3 km in 10.4 min at a constant velocity.
The acceleration of gravity is 9.8 m/s^2
What is Shawn's kinetic energy?


Homework Equations


F = ma
Ff = u * Fn
Fn = mg
avgV = x/t
x = 1/2(Vf + Vi)t


The Attempt at a Solution



ok so I converted km to m and min to s:
x = 1300m
t = 624s
and then i used avgV = x/t so avgV = ~2.08333 m/s

i have no idea what kinetic energy is, this hasn't been covered in class yet but I wanted to get ahead because I think I am coming down with the flu. The answer to the problem is supposed to be 94.4014 J but I have no idea how to set this problem up to get this. Please help me! Thanks.
 
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  • #2
The kinetic energy = 1/2*m*v^2
 
  • #3
THAAATTSS what i needed ooohhh maaann thanks rl.bhat!
so it would be (0.5)(43.5)(2.08333)^2 = 45.3124 J

thanks again!
 

1. What is a force and how does it affect motion?

A force is a push or pull on an object that can cause it to accelerate or change its direction. Forces can either be balanced, where the net force is zero and there is no change in motion, or unbalanced, where the net force results in a change in motion.

2. What is kinetic energy and how is it related to forces?

Kinetic energy is the energy an object possesses due to its motion. It is directly related to an object's mass and velocity, and is affected by forces acting on the object. The greater the force, the greater the acceleration and change in kinetic energy.

3. How do you calculate the amount of kinetic energy an object has?

The formula for calculating kinetic energy is: KE = 1/2 * m * v^2, where KE is kinetic energy, m is mass, and v is velocity. This formula shows that kinetic energy is directly proportional to mass and the square of velocity.

4. Can forces change an object's kinetic energy?

Yes, forces can change an object's kinetic energy. When a force acts on an object, it can either increase or decrease the object's velocity, thus changing its kinetic energy. For example, a force can increase an object's speed, resulting in an increase in kinetic energy.

5. How can you use the concept of forces and kinetic energy to solve problems?

To solve problems involving forces and kinetic energy, you can use the principles of Newton's laws of motion and the equations for calculating force and kinetic energy. By understanding how forces affect motion and how kinetic energy is related to mass and velocity, you can analyze and solve various problems involving these concepts.

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