Homework Help: Can someone double check

1. Jan 6, 2005

butz3

i have this pratice assignment that i would like some one to double check to make sure i did it right. if I got the question wrong would you please explain what i did wrong thaks so much so here it goes.
Multiple Choise
1) th unit that is equivalent to a joule is found my manipulating units of
a) force x distance/ time
b) force/ acceleration
c) mass x speed squared - this is what i picked
d) work/ mass
2)an experiment was done by measuring the work done moving an object with mass m up a ladder. work was calculated by measuring the force needed to lift the object and multiplying it by the distance moved. an algebraic value for the slope of this is
a) mg
b)g - this is what i picked
c)m
d)1/g
3) two cars collide and stick together on a frictionless, horizontal surface. which of the following statements is likely true?
a)momentum will not be conserved and kinetic energy will not be conserved
b)momentum will be conserved and kinetic energy will not be conserved - i picked this one
c)both momentum and kinetic energy will be conserved
d)momentum will not be conserved and kinetic energy will be conserved
4)during and experiment with simple harmonic motion, a group of students used the period of a pendulum to calculate g, the acceleration due to gravity. they measured the period and the lenght of the pendulum. the value of g is found by using which of these equations?
a) g=4pie^2l/t^2- i picked this one
b)g=4piel/t^2
c)g=2piesquare root l/t
d)g=t^2/4pie^2l
5)if the distance between two charges was doubled, the resulting force of electrostatic attration would be
a)the same
b)half as great
c)twice as great
d)one quarter as great - i picked this one
6)a positive charge moves form left to right across a magnetic field and experiences a magnetic force which is directed upwards along the page. the direction of the external magnetic field is?
a)left to right
b)right to left
c)directed into the plane of the page
d)directed out of the plane of the page - i picke this one.
numerical responce
1)a 6.00 kg steel ball falls of a ledge that is 4.50 m high. its speed upon impcat is N m/s. the value of n is? my answer is 9.40m/s
2)a hair dryer draws 1.5A form a 120V source. if the hair dryer is used for 10 min the energy consumed is b x 10^w J. the value for b is? my answer is 1.1X10^5 J
3)an alpha particle which possesses 1.36x10^-13 J of kinetic energy enters a magnetic field of 4.60x10^-3T. the deflecting force on the alpha paricle is b x10^-w N. the value for b is? my answer is 4.7x 10^-15N.