A microwave oven of mass 13.0kg is pushed a distance 8.80m up a ramp

AI Thread Summary
To analyze the work done on a microwave oven pushed up a ramp, the kinetic energy theorem is applicable, specifically using the equation Δ(KE) = W_net. The work done can be calculated by considering the forces involved, including friction, which opposes motion and thus is treated as a negative value in calculations. The net work is determined by subtracting the work done against friction and gravitational forces from the applied force. Friction will decrease the kinetic energy of the system, as it acts against the direction of motion. Understanding these dynamics is crucial for accurately calculating the change in kinetic energy.
nouvelague
Messages
2
Reaction score
0
Homework Statement
A microwave oven of mass 13.0 kg
is pushed a distance 8.80 m
up the sloping surface of a loading ramp inclined at an angle of 38.3 ∘
above the horizontal, by a constant force F⃗
with a magnitude 150 N
and acting parallel to the ramp. The coefficient of kinetic friction between the oven and the ramp is 0.240.


Part D
Use your answers to parts (A), (B), and (C) to calculate the increase in the oven's kinetic energy.
Take the free fall acceleration to be 9.80 m/s2
. Express your answer using two significant figures.
Relevant Equations
W = change in KE
-change in U + Wfriction = change in KE
For this one, am i supposed to use W = change in KE where i calculate work as ((F - friction - mgsintheta) times d), or am i supposed to do the change in -mgh plus Wfriction = change in KE (where if it is in this case, is the friction going to be a negative number?)
 
Physics news on Phys.org
Since friction is involved, you are supposed to use the kinetic energy theorem $$\Delta (KE)=W_{\text{net}}.$$ I assume that in the previous parts you have calculated all the works that are needed.
 
nouvelague said:
where if it is in this case, is the friction going to be a negative number?
Will the friction occurring here increase or decrease the kinetic energy?
 
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »
Thread 'Minimum mass of a block'

Thread 'Minimum mass of a block'

Here we know that if block B is going to move up or just be at the verge of moving up ##Mg \sin \theta ## will act downwards and maximum static friction will act downwards ## \mu Mg \cos \theta ## Now what im confused by is how will we know " how quickly" block B reaches its maximum static friction value without any numbers, the suggested solution says that when block A is at its maximum extension, then block B will start to move up but with a certain set of values couldn't block A reach...
View full post »

Similar threads

Coefficient of Friction question for a cart going down a wooden ramp
Replies
18
Views
3K
Distance of box pushed up incline by spring
Replies
1
Views
3K
Stopping distances on a downward slope
Replies
3
Views
2K
Conundrums on energy and graphs
Replies
5
Views
1K
How far does the block travel up the incline?
Replies
1
Views
4K
Energy/Work Problem: Friction of sliding down pole
Replies
5
Views
4K
Two bodies connected with an elastic thread moving with friction
Replies
6
Views
1K
D’Alembert Vs Conservation of Energy
Replies
3
Views
5K
Questions Regarding a Cat Going Up a Ramp
2
Replies
56
Views
4K
What is the deceleration of a snowboarder going up a 5.0° slope?
Replies
2
Views
13K

Hot Threads

Recent Insights

Back
Top