What is the speed of the block after this displacement?

In summary, the conversation discusses a problem involving work done by various forces on a block being pushed up an incline. The first three parts are completed, but the last part, which involves finding the speed of the block, is causing difficulty. The formula W = .5m(v^2) is mentioned and the correct answer is eventually found by considering the total work done on the object.
  • #1
meganw
97
0

Homework Statement



I did the first 3 parts of the question, but I can't seem to get the right answer on the last one.

(a) How much work is done by the horizontal force Fp on the 20 kg block when the force pushes the block 3.6 m up the 30° frictionless incline?
467.7 J
(b) How much work is done by the gravitational force on the block during this displacement?
-352.8 J
(c) How much work is done by the normal force?
0 J
(d) What is the speed of the block (assume that it is zero initially) after this displacement?


Homework Equations


F=ma
K=.5m(v^2)

The Attempt at a Solution



I know that W = .5m(v^2) in this case, and since on D, (thats the one I have a question on), I'm trying to find Velocity, I can use this formula. I tried

467.7 = .5m(v^2)

and got v=6.83 but that's wrong.

Thank you so much for your help!

=)
 
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  • #2
What's the TOTAL work done on the object?
 
  • #3
Hey, I didn't think to do that, THANK YOU I got it right! =) =)
 

1. What is the definition of speed?

The speed of an object is the rate at which it covers a certain distance. It is a measure of how fast something is moving.

2. How is speed different from velocity?

While speed only measures the rate of motion, velocity takes into account the direction of the motion as well. It is a vector quantity, meaning it has both magnitude and direction.

3. What factors affect the speed of an object?

The speed of an object can be affected by various factors such as the force applied, the mass of the object, and the surface on which it is moving. Other factors include air resistance, friction, and the shape of the object.

4. How is speed calculated?

Speed is calculated by dividing the distance traveled by the time it takes to cover that distance. The formula for speed is: speed = distance / time. It is typically measured in units of meters per second (m/s) or kilometers per hour (km/h).

5. Can an object have a constant speed while changing its direction?

Yes, an object can have a constant speed while changing its direction. This is known as uniform circular motion, where the speed remains the same but the direction of motion changes constantly.

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