Physics Work,Power & Energy Level: High School
Conservation of Energy
Consider a compact car that is being driven at 118 km/h . The acceleration of gravity is 9.8 m/s2 . From what height would the car have to be dropped to have the same kinetic energy ? Answer in units of m .
Physics Work,Power & Energy Level: High School
Conservation of Energy
A 8.8 kg mass is attached to a light cord that passes over a massless, frictionless pulley . The other end of the cord is attached to a 2.2 kg mass . The acceleration of gravity is 9.8 m/s2 . Uses conservation of energy to determine the final speed of the first mass after it has fallen (starting from rest) 6.3 m . Answer in units of m/s .
Physics Work,Power & Energy Level: High School
Conservation of Energy
A frictionless pendulum of length 3 m swings with an amplitude of 10 degrees . At its maximum displacement , the potential energy of the pendulum is 10 J . What is the kinetic energy of the pendulum when its energy is 5 J ?1) K = 5 J
2) K = 10 J
3) K = 15 J
4) K = 6.7 J
5) K = 3.3 J
Physics Work,Power & Energy Level: High School
Elastic Potential Energy
A block of mass m slides on a horizontal frictionless table with an initial speed V0 . It then compresses a spring of force constant k and is brought to rest . The acceleration of gravity is 9.8 m/s2 . How much is the spring compressed x from its natural length ?a) x = v0 (m/kg)
b) x =v0 (mg/k)
c) x = v0 x Square root of m/k
d) x = (v0 squared /2g)
e) x = v0 x square root of k/m
f) x = (v0 squared /2m)
g) x = v0 x square root of mg/k
h) x = v0 (mk/g)
i) x = v0 (k/gm)
j) x= v0 x square root of k/mg
Physics Work,Power & Energy Level: High School
Elastic Potential Energy
It takes 2.39 J of work to stretch a Hooke’s-law spring 4.3 cm from its unstressed length . How much the extra work is required to stretch it an additional 15.3 cm ? Answer in units of J .
Physics Work,Power & Energy Level: High School
Power
Water flows over a section of Niagara Falls at a rate of 1.47 x 10^6 kg/s and falls 30 m . The acceleration of gravity is 9.8 m/s2: How many 40 W bulbs can be lit with this power ?
Physics Work,Power & Energy Level: High School
Potential Energy
The potential energy between two atoms in a particular molecule has the form U(x) = (3.1/x^8)-(5.3/x^4) where the units of x are length and the numbers 3.1 and 5.3 have appropriate units so that U(x) has units of energy. What is the equilibrium separation of the atoms (that is the distance at which the force between the atoms is zero) ?
Physics Vectors Level: High School
Vector
Find the scalar product of the vectors in figure at “click here” , where theta = 121 degree and F = 33.5 N .
Physics Work,Power & Energy Level: High School
Power
A 550 kg elevator starts from rest . It moves upward for 2.00 s with constant acceleration until it reaches its cruising speed , 1.75 m/s .a) What is the average power of the elevator motor during this period ?
Physics Work,Power & Energy Level: High School
Elastic Potential Energy
An object of mass m starts from rest and slides a distance d down a frictionless incline of angle theta . While sliding ,it contacts an unstressed spring of negligible mass as shown in the figure at “click here” . The object slides an additional distance x as it is brought momentarily to rest by compression of the spring . (Use theta for theta , g for acceleration due to gravity , and m , k and x as necessary.)
Physics Work,Power & Energy Level: High School
Conservation of Energy
A particle of mass m = 6.20 kg is released from point A and slides on the frictionless track down in the figure at “click here”. (ha = 7.70 m)a) Determine the particle’s speed at point B and C .
b) Determine the network done by the gravitational force in moving the particle from A to C.
Physics Waves And Oscillations Level: High School
Echo
A sailor strikes the side of his ship just below the surface of the sea . He hears the echo of the wave reflected from the ocean floor directly 3.22 s later . How deep is the ocean at this point ?
Physics Waves And Oscillations Level: High School
Standing Waves
The velocity of waves on a string is 265 m/s . If the frequency of standing waves is 133 Hz, how far apart are the nodes ?
Physics Waves And Oscillations Level: High School
Standing Waves
A violin string vibrates at 280 Hz when unfingered . At what frequency will it vibrates if it is fingered one-fourth of the way down from the end ?
Physics Waves And Oscillations Level: High School
Standing Waves
One end of a horizontal string of linear density 4.47 x 10^-4 kg/m is attached to a small-amplitude mechanical 60.5 Hz vibrator. The string passes over a pulley , a distance L = 1.59 m away , and weights are hung from this end , as seen in the figure at “click here” . What mass must be hung from this end of the string to produce one loop of a standing wave ? Assume the string at the vibrator is cathode , which is nearly true .a) What mass must be hung from this end of the string to produce two loops of a standing wave ?
