Calculating Forces and Acceleration

  • Thread starter Thread starter airelemental135
  • Start date Start date
  • Tags Tags
    Acceleration Forces
AI Thread Summary
To solve the problems presented, one should start by applying Newton's laws of motion, particularly F=MA, and creating free body diagrams to visualize the forces involved. For question 28, the horizontal retarding force can be calculated using the applied force and the angle of the handle, while the normal force requires considering the weight of the mower and the vertical component of the applied force. In question 30, the tension in the cords can be determined by analyzing the forces acting on each bucket at rest and under acceleration. Question 32 involves calculating the force needed to maintain constant speed and the resulting acceleration when that force is increased. Understanding these fundamental principles is crucial for accurately solving the problems.
airelemental135
Messages
13
Reaction score
0
Does anyone know how I can do 28, 30, and 32, reproduced below?

28. A person pushes a 14.5-kg lawn mower at constant speed with a force of 88.0 N directed along the handle, which is at an angle of 45.0 degrees to the horizontal. Calculate (a) the horizontal retarding force on the mower, then (b) the normal force exerted vertically upward on the mower by the ground, and (c) the force the person must exert on the lawn mower to accelerate it from rest to 1.5 m/s in 2.5 seconds (assuming the same retarding force).

30. One 3.0-kg paint bucket is haning by a massless cord from another 3.0-kg paint bucket, also hanging by a massless cord. (a) If the buckets are at rest, what is the tension in each cord? (b) If the two buckets are pulled upward with an acceleration of 1.60 m/s^2 by the upper cord, calculate the tension in each cord.

32. A window washer pulls herself upward using the bucket-pulley apparatus. (a) How hard must she pull downward to raise herself slowly at constant speed? (b) If she increases this force by 10 percent, what will her acceleration be? The mass of the person plus the bucket is 65 kg.
 
Physics news on Phys.org
What have you tried so far? On problems like this, it is always best to draw a free body diagram with the forces, sum them up and use good ol' F=MA.
 

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »
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 »

Similar threads

Newtonian Mechanics/Forces Question
Replies
4
Views
1K
A person pushes a 10.0 kg lawn mower at constant speed with a force of
Replies
6
Views
6K
Solving for Tension with a massless cord
Replies
2
Views
3K
Tension Problems Given Two Weights
Replies
3
Views
3K
Newton's laws with buckets and strings
Replies
2
Views
2K
A window washer pulls herself upward using the bucket-pulley
Replies
1
Views
4K
Swinging Ball at Top of Circle: Forces & Energies
Replies
16
Views
2K
Window Washer w/ Bucket-Pulley Apparatus
Replies
18
Views
4K
Understanding Tension Forces in a Slowly Rising System
Replies
1
Views
1K
Pulling yourself up with a pulley
Replies
9
Views
9K

Hot Threads

Recent Insights

Back
Top