Physics 11, kinetic energy problem

In summary, the conversation involves someone asking for help with a physics problem involving a tennis ball being hit by a racquet. The problem asks for the kinetic energy of the ball as it leaves the racquet, given its mass and contact time with the strings. The conversation includes hints and equations to help solve the problem, and ends with the correct answer of 169J. There is also a mention of other questions that the person may have.
  • #1
Iceclover
59
0
Hey if anyone could help me work through a couple of problems that would be great!:smile:

Homework Statement



It is not uncommon during the service of a professional tennis player for the racquet to exert an everage force of 150.0N on the ball. If the ball has a mass of 0.060kg and is in contact with the strings of the racquet for 0.030s what is the kinetic energy of the ball as it leaves the racquet? Assume the ball starts from rest


Homework Equations



Ek=1/2mv^2

The Attempt at a Solution


I'm not sure really where to start here...
 
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  • #2
A hint: impulse.
 
  • #3
Well, you know what you'll need to find Kinetic Energy--mass and velocity. You're given mass. Can you think of any other equations that might help you find velocity?
 
  • #4
what do i do once I've figured that out?
 
  • #5
d=vt but i don't have a distance either
 
  • #6
Once you've figured what out?
 
  • #7
oh my god i think i got it, will someone let me know if i got it right, just let me work it out.
 
  • #8
There is no need to create so many posts. :wink:
 
  • #9
i got 169J
 
  • #10
Looks OK to me, whose brain is fried!
 
Last edited:
  • #11
Iceclover said:
i got 169J

That's correct.
 
  • #12
p=Ft
p=150(0.030)
p=4.5

p=mv
4.5=(0.06)(v)
v=75m/s

Ek=1/2m^2
Ek=1/2(0.060)(75^2)
Ek=169J
 
  • #13
Ok i have a couple of other question so if anyone wants to stick around and help...?
 

Related to Physics 11, kinetic energy problem

1. What is kinetic energy?

Kinetic energy is the energy an object possesses due to its motion. It is calculated as half the mass of the object multiplied by the square of its velocity.

2. How is kinetic energy different from potential energy?

Kinetic energy is the energy of motion, while potential energy is the energy an object has due to its position or configuration. Kinetic energy can be converted into potential energy and vice versa.

3. How is kinetic energy measured?

Kinetic energy is measured in joules (J) in the International System of Units (SI).

4. Can kinetic energy be negative?

No, kinetic energy cannot be negative. It is always a positive value, as it is a measure of an object's motion.

5. How does mass and velocity affect kinetic energy?

Kinetic energy is directly proportional to an object's mass and the square of its velocity. This means that as mass and velocity increase, so does kinetic energy.

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