Physics Modern Physics Level: High School
Radioactivity
A radioactive element decays according to the equation N(t) = N0 e-^3 t , where N0 is the original number of atoms , and N(t) is the number of atoms remaining after a time t measured in days . If N0 = 2 x e 7, find the time after which 2 x e 5 atoms remain .
Physics Rotational Mechanics Level: High School
Circular Motion
An object moving in a circle of radius 2 meters moves through a 30 degrees arc . What distance does it travel along this arc ?
Physics Kinematics Level: High School
Relative Motion
Two planes (1and 2) start out at airports separated by 2200 kilometers. They take off simultaneously , and travel in opposite direction directly towards each other. Plane 1 travels at 500 km/h plane 2 travel at 600 km/h . Determine the time at which they meet .
Physics Measurements Level: High School
Calculate the volume of the earth (radius 6.38 x e6 m) .
Physics Rotational Mechanics Level: High School
Circular Motion
A ball on the end of a string moves in a circle at a speed of 5 m/s , making one complete revolution in 2 seconds . What is the radius of the circle ?
Physics Kinematics Level: High School
One Dimensional
If the initial speed of an object with constant acceleration is 5 m/s and the acceleration is 2m/s^2 , what is the speed of the object after 10 seconds ?
Physics Measurements Level: High School
There are 50 liters of water in a full cylinder tank 1 meter high . What is the volume of water (in liters) remaining when the height of the water in the tank is 10 centimeters ?
Physics Kinematics Level: High School
A car is located 20 meters from a store when the car starts moving away from the store , down the main street , at 5 meters /second . Express the car’s location (in meters) as a function of time t (in seconds) , using the store as the origin:a) x(t) = 5t^2+20
b) x(t) = 5t + 20
c) x(t) = 5t -20
d) x(t) = 2.5t^2+5t+20
Physics Kinematics Level: High School
Translate the following sentence into equations: Car A is at the same position that Car B was one second earlier :a) xa(t+1) = xb(t)
b) xa(t) = xb(t+1)
c) xa(t) = xb(t-1)
d) xa(t-1)= xb(t)
Physics Force & Laws Of Motion Level: High School
Spring Constant
A force of 100 N is needed to compress a spring by 0.02 meters . IF the force is directly proportional to the compression distance, determine the force required to compress the spring by 0.04 meters .
Physics Force & Laws Of Motion Level: High School
A spring is suspended vertically from a fixed support . The spring constant is k = 100 N/m . When a heavy object is attached to the bottom of the spring , the spring stretches by 0.2 meters . Determine the weight (force of gravity) pulling on the object , as well as the object’s mass .
Physics Vectors Level: High School
At a certain time a plane is 100 kilometers due north of Montreal . One hour later its location is 500 kilometers southeast of the city . If the plane moves in a straight line , determine its speed and the distance it has traveled .
Physics Gravitation Level: High School
Geosynchronous Satellite
Find the altitude of a geosynchronous satellite above Earth’s surface . Start by writing an equation that relates the period , radius , and speed of the orbiting satellite . Then apply the Newton’s second law to the satellite . You will have two equations with two unknowns ( the speed and radius) . Eliminate the speed algebraically and solve for the radius .
Physics Rotational Mechanics Level: High School
Rotational Kinetics
Massimo , a machinist , is cutting threads for a bolt on a lathe . He wants the bolt to have 18 threads per inch . If the cutting tool moves parallel to the axis of the would-be bolt at a linear velocity of 0.080 in ./s , what must the rotational speed of the lathe chuck be ensure the correct thread density ? [Hint : One thread is formed for each complete revolution of the chuck.]
Physics Rotational Mechanics Level: High School
Apparent Weight
A little girl is having fun on a swing of length 8.0 m . If her weight is 180 N, find her apparent weight ,a) at the lowest point , where her speed is 9.7 m/s
b) at the highest point , where the swing is at an angle theta = 75 degree to the vertical .
