May the force be with you.
Is there one equation for normal force?
No! It depends on the situation
What is the equation for friction?
Ff = (mu)*FN
What is the tension for a hanging mass at rest? Write your answer in variables.
T = mg
A box sits at rest on a ramp? What force acts on the box to keep it on the ramp?
Friction
An object moves foward with a constant velocity. Which is true?
A.) The net force cannot be determined
B.) The acceleration is not zero
C.) The net force is zero
C
A 5 kg box rests on a table. Draw the free-body diagram for the box.
Check FBD (FN = Fg)
What is the difference between static friction and kinetic friction?
Static friction: Two surfaces are not moving relative to each other
Kinetic Friction: Two surfaces are moving relative to each other
A 500 kg box is being held up by a crane. What is the force of tension in the crane?
4900 N
What is the component of force acting parallel for an object of mass m on a ramp of angle theta? Write using variables.
Fgparallel = m*g*sin(theta)
If an object is at rest, can you conclude that there are no forces acting upon it?
No, even if an object is at rest, forces are still acting upon the object to keep at equilibrium in rest.
Two dogs are pulling on a bone. One pulls with 32N of force to the right and one pulls with 35N to the left. What is magnitude and direction of the net force of the bone?
3N to the left (-3N)
A 7kg box is pushed to the right with 10 N of force. A force of friction of 4.5 N is also present. What is the acceleration of the object?
a=0.78 m/s2
A 3 kg box is being held up by a massless cord. What is the tension in the cord?
29.4 N
What is the component of force acting perpendicular for an object of mass m on a ramp of angle theta? Write using variables.
Fgperp = m*g*cos(theta)
Louis pushes a block with 31N of force. He observes that it has a constant linear acceleration of 2.1 m/s2 . What is the mass of the block?
A.) 12.1kg
B.) 14.76kg
C.) 1.41kg
D.) 15.12kg
E.) 33.22kg
B
A 2.5 kg box is pushed so it slides on a frictionless floor with an acceleration of 4 m/s2. What is the force used to push the box?
10 N
A sled with a weight of 62 N slides across a flat, snowy surface. What is the force of friction if the coefficient of kinetic friction is 0.09?
Ff = 5.58 N
A force of tension is used to pull a mass of 100kg with an acceleration of 2 m/s2. What is the tension?
200 N
Draw a free body diagram illustrating the components of force acting on a body at rest on an inclined plane. Label them clearly.
See drawing
A mosquito collides head-on into a car with a force of 0.10 N. What is the force on the mosquito from the car?
A.) Larger than 0.10 N
B.) Equal to 0.10 N
C.) Less than 0.10 N
B
A skier with a mass of 82kg slides down a snowy slope at an angle of 42 degrees. Find the coefficient of kinetic friction for the skier if the friction is known to be 51N.
0.085
If a box with of 4.48kg is pushed across a floor experiences a force of friction of 2.64N, what is the coefficient of kinetic friction between the surfaces?
0.06
Find the net force acting on a box that is pulled to the right with a force of 20N and 30N. The box is also pulled to the left with a force of 40N. Draw a free body diagram and label the forces. Find the net force.
Check diagram, net force is 10N to the right.
What is the force of tension holding a box of mass m stationary on a ramp of angle theta? Write your answer in variables.
T = m*g*sin(theta)
Which has more inertia? A 1500kg truck at rest or a 0.5kg ball in motion?
A 1500kg truck