The work done occurs only in the direction the block was moved - horizontally. Work is given by:
W = F(h) * d
Where F(h) is the force applied in that direction (horizontal) and d is the distance in that direction. In this case, F(h) is the horizontal component of the applied force, F(app). However, the question doesn't give us F(app), so we need to find it some other way.
Since the block is moving at a constant speed, we know the horizontal forces must be balanced so that the net force is 0. This means that F(h) must be exactly balanced by the friction force, f. We can express F(h) as a function of F(app):
F(h) = F(app)cos(23)
Friction is a little trickier - since the block is being PUSHED into the ground a bit by the vertical component of the applied force, F(v), the normal force, N, is actually a bit more than mg:
N = mg + F(v) = mg + F(app)sin(23)
Now we can get down to business and solve for F(app) - as mentioned above:
F(h) = f
F(h) = uN
F(h) = u * (mg + F(v))
F(app)cos(23) = 0.20 * (33 * 9.8 + F(app)sin(23))
F(app) = 76.8
Now that we have F(app), we can find the exact value of F(h):
F(h) = F(app)cos(23)
F(h) = 76.8cos(23)
F(h) = 70.7
And now that we have F(h), we can find W:
W = F(h) * d
W = 70.7 * 6.1
W = 431.3
Therefore, the work done by the worker's force is 431.3 J. This also represents the increase in thermal energy of the block-floor system.
Answer:
The answer is given here would be a simplified equation, seeing as there are some missing variables in the question.
<u>F1 = T- 46, 674.656 gm/s² </u>
Explanation:
<em>Note: Once we have the mass of the second object and/or acceleration of the cord, we can solve for the force of the ground acting on the box.</em>
To calculate the force caused by gravity on the basic pulley system we use the following equation:
F2 = M2 x g; where g= gravitational acceleration (a constant equal to 9.8 m/s²). The mass M2 = 10.5 lb = 4762.72g
∴ F2 = 4762.72g x 9.8 m/s²
= 46, 674.656 gm/s² or 46, 674.656 N
But since this F2 is acting in a downlowrd direction, it would be negative.
Tension of the cord, T = Mass, x × acceleration. ( x is in the pulley diagram)
⇒ F1 = T - F2
<u>F1 = T- 46, 674.656 gm/s² </u>
Answer:
if the frequency is double, the wavelength is only half as long
Explanation:
She misses. She should have accelerated faster in order to get to her target.