1. How much more gravitational potential energy does a 1.3 kg hammer have when i

Question

1. How much more gravitational potential energy does a 1.3 kg hammer have when it is on a shelf 1.8 m high than when it is on a shelf 0.70 m high?___J

2. A 0.300 kg ball is thowrn vertilly pd with an intial sp of 18.0 m/s.

part A. what is the maxiumun height rached by the ball?h=__m

3. if the work required to speed up a car from 15 km/h to 24 km/h is 7.58*10^-3J., what would be the work required to increase he car's speed from 24 km/h to 34 km/h?W=__J

4. a 1100 kg autoobil travels at 80 km/h

partA what is the kinect energy?K=___J

part B what net work would be required to bring it to a stop?W=__J

5. 5.00 kg block slides down a frictionless plane iclined 27 degrees to the horizontal.

part A if the lenght of th plne's surface is 3.00 m, how much work is doen/W=__J

part B by what force is the work done?

friction force, normal force, or gravitational force

Explanation / Answer

1. U = mgh
U = mg(h) so
U=1.3(9.8)(1.8-0.7)=14.014 J

2.Energy conservation shall apply :
1/2mVo^2 = m*g*h
h = Vo^2/2g = 18^2/19.6 = 16.53 m approx.

3.  By work energy theorem:-
=>W = KE
=>7.58*10^3 = 1/2 x m x [(24 x 1000/3600)^2 - (15 x 1000/3600)^2]
=>m = 559.75 kg
2nd condition:-
=>W = KE
=>W = 1/2 x m x [(vf)^2 - (vi)^2]
=>W = 1/2 x 559.75 x [(34 x 1000/3600)^2 - (24 x 1000/3600)^2]
=>W = 12525.27J
=>W = 1.3 x 10^4 J

4 A KE=0.5*m*v^2=0.5*1100*80*1000/3600=12222.22 J = 12.2 kJ

B Net work to stop (KE = 0) = decrease in KE = 12.2 kJ

5. F=mgsin theta = 5*9.8*sin27 =22.25 N

W=F.D =22.25*3 =66.74 J

gravitational force

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.