An obnoxious brat assigns his 0.0183-kilogram pet mouse Mickey the role of stunt
ID: 1471389 • Letter: A
Question
An obnoxious brat assigns his 0.0183-kilogram pet mouse Mickey the role of stunt mouse by stuffing him into a spring gun and shooting him up into the air at some angle. During the launch process the spring transfers 0.638 J of energy into the 'mouse + Earth + gravitational fields' system. Because he is fired at an angle, when Mickey reaches his maximum height, he is still moving horizontally with a speed of 2.17 m/s. How high above his initial location in the gun does Mickey soar? (In case you are worried, a miniature parachute opens at this point and Mickey lands safely. The brat is slightly less obnoxious than we thought.) Take g = 9.81 m/s^2.Explanation / Answer
1) energy spring =1/2 kx2
=0.5*0.638*x2
we don't know the x value so we are using work=force*displacemt
W=Fd
d=W/F
here we don't know the F value so
we know newton's second law F=ma using this equation
F=0.0183*2.17
F=0.0397.
this value substituting the above equation
d=0.638/0.397
d=16.07 cm.
so the energy spring=1/2 kx2
=(0.5)*(0.638)*(16.07)2
=82.38
2) Energy that is still K.E=1/2mv2
=(0.5)(0.0183)*(2.17)2
=0.04308
3)The rest of the energy must be in GPE=mgh
=(0.0183)*(9.81)*(6.625*10-34)
= 1.189*10-34
take (2) from (1) and the rem