forces, torque, work, and tension

Equation to solve for net forces

Fnet=ma

Equation to find Fg

Fg=mass(9.80)

Equation for tension

T-mg=ma

How to find minimum force needed

F=Fs+mgsintheta

To find friction force coefficient

Fk= Fperp-Fnet

Equation for

What magnitude of force applied perpendicular to the top of a box is needed to prevent the box from starting to slide

F= mgsintheta/mews - mgcostheta

Find friction force with work

Fk= Wf/d

Find acceleration for 2 body problems

A= m1g-m2gsintheta-mewkm2gcostheta / m1+m2

Steps to solve a problem given weight, angle, and coefficients when trying to find the magnitude of the box’s acceleration then the magnitude of force perpendicularly to top of box

1. Set up FBD

2. Find MG

3. Then do the cos and sin for parallel and perpendicular

4. Find max depending on static or kinetic

5. Then calculate the net force by subtracting the max from the opposing force (sin) and dividing by the weight

Part b)

1. Plug in numbers for this equation from work done in part one

2. F= mgsintheta / static coefficient - mgcostheta

If we know an object is moving at constant velocity we may assume

The net force acting on the object is zero

The figure shows a block on an inclined plane what is the expression for the normal force acting on the block

Mgcostheta

A block of mass 4 kg rests on a horizontal surface where the coefficient of kinetic friction between the 2 is .2. A string attached to the block is pulled horizontally resulting in a 3m;/s ² acceleration by the block. Find the tension in the string

(4)(9.8)=39.2

T-Ukn=ma

Ukn = .2(39.2)=7.84

Ma= (4)(3)=12

Plug in to og equation then solve for T

20N

A 3kg bowling ball experiences a net force of 8 what will be its acceleration

A=fnet/m

8/3=2.667

If we know that a nonzero net force is action on an object which of the following must we assume regarding the objects condition. The object is

Being accelerated

Petra pushes a cart across a rough horizontal floor a frictional force of 28 acts to oppose the motion of the crate and Petra pushes with a horizontal force of 36.4. If the net work Petra does is 94.5 through what distance did she push the crate

W=fdcostheta

94.5=36-28=86.5

86.5=dcostheta

86.5=dcos180

D= 2.60

A box slides across a floor and comes to rest the work done by the frictional force on the box is

Negative

The unit of work joule is dimensionally the same as

Newton-meter because its force x distance

A very light cart holding a 100N box is moved at constant velocity across a 10m horizontal surface what is the net work done on the system( work+cart) in the process

Zero

A 26n crate starting at rest slides down a rough 4.8m long ramp inclined at 2nd egress with the horizontal 18joules of energy is lost from the system due to friction. What will be the speed of the crate at th bottom of the incline

Answer is 4.49 but i dont know why

Which of the following quantities is equal to the impulse that acts on an objet assuming there is only one unbalanced force acting on that object

Both change in p^→ and Fchanget

What is conserved in an inelastic collision

Momentum of the system

An astronaut is stranded in space far form any planet or star of significant mass so all gravitational forces are negligible small. That means we can consider the astronaut of mass 75kg and the 2.5kg tool that he is holding to be an isolated system. The astronaut is initially at rest if he throws the tool to the left with a velocity of 10m/s² what will be the astronauts recoil velocity?

Answer=.33m/s to the right

Explanation

2 loaded carts are traveling towards each other on a frictionless horizontal track. The 2 carts each have a mass of 200kg and speed of 5m/s. They have an elastic collision. What is the speed of cart 1 after the collision

5m/s because the elastic collision preserves momentum

What if instead in the coal cart collision described in the previous problem the 2 carts couple together when they collide so the carts are now joined.m what is the speed of the pined carts after the collision

5m/s because it is still preserved but proven through math using weird long equation with m and v