Newton's Laws
(1 minute) You thought this was a force equation? Well what if I told you that my dog, Rocko pushed a box 4 kilograms in weight to the other side of the room with a measured force of 60 Newtons. What would be his acceleration huh?!
15 m/s2
State and identify each component of Hooke’s Law.
F=kL
F- force
k- spring constant
L- amount of deformationThis type of friction resists the motion of an object that is already sliding across a surface.
What is kinetic friction?
What is the term for force that pushes an object into the center of a circular path?
Centripetal force?
Acceleration due to gravity at Earth's surface
9.8 m/s2
The property of a body to remain at rest or to remain in motion with constant velocity
What is inertia?
This equation, ΔL=(1/Y)(F/A)L0, describes how much a material stretches/compresses under stress using its _____ _________, ___-________ ___, and _________ ________.
Original length, cross-sectional area, Young’s modulus
This type of friction resists the initiation of motion between two surfaces in contact.
What is static friction?
What is the velocity that is parallel to a point on the circle called?
Tangential velocity
Equation for gravitational potential energy
Ug=mg(delta)y
What are Newton's three laws of Motion?
First Law is Inertia, Second Law is Concept of a system or F=ma, Third Law is for every action, there is an equal opposite reaction
What is Angela's favorite color?
Yellow lol
A 10 kg box is being pushed across a floor with a coefficient of kinetic friction of 0.3. What is the force of kinetic friction acting on the box?
29.4 N
What law explains how an object stays in motion?
Newton's First Law
Isaac Newton
(2 minutes) If four students push a desk across the room with friction of 25 N, a mass of 160kgs, and travel at an acceleration of 0.5 m/s^2, what is their Net force?
55 N
(3 minutes) A steel suspension bridge uses a main cable to support its weight. The unsupported span of the cable is 2,800 m, and the cable is subjected to a maximum tension of 2.5×106 N. The cable has a diameter of 4.8 cm, and Young's modulus for steel is 210×109 N/m2. Calculate the amount of stretch in the steel cable.
18.42 m
If a box is stationary on a flat surface, the force required to begin sliding it depends on this coefficient, which is a ratio of the maximum static friction to the normal force.
What is the coefficient of static friction?
What is the equation for centripetal acceleration?
What doesn't melt steel beams?
Jet fuel
(3 minutes) A 50kg supermarket customer exerts a force of 270 N onto the floor when pushing a cart that is 20kgs. The cart also includes 4kgs of meat, 6kgs of dairy, 10kgs of frozen foods, and 2kgs of candy. What is their acceleration when friction is applied to the cart's wheels is 15 N? What is the force exerted on the cart by the customer?
Acceleration is 2.8m/s2 and the force on the cart is 131.4 N
(3 minutes) Calculate the change in length of the upper leg bone (the femur) when a 80.0 kg man supports 72.0 kg of his mass on it, assuming the bone to be equivalent to a uniform rod that is 40.0 cm long and 2.00 cm in radius. Young’s modulus for bone compression is 9×10^9 N/m2.
2.77×10-5 m
The force of friction that acts when an object transitions from rest to motion is equal to the product of the normal force and this coefficient.
What is the coefficient of kinetic friction?
What is the period of rotation of earth in seconds? What is the angular velocity of earth? Given that earth has a radius of 6.4 x106 at it's equator, what is the linear velocity of earth?
86400 seconds, 7.27x10-5 rad/s, vt=465 ms/
A rock with a mass of 2kg is dropped from a height of 10 meters near Earth's surface. Air resistance is negligible. What is the gravitational force acting on the rock?
19.6N