Physics
posted by Anonymous .
please can u check my answer
Here are the questions:
1. A 0.45 kg book is resting on a dessktop 0.64 m high. Calculate the book's potential energy relative to
a)the desktop? b)the floor.
2. A 0.636 kg basketball has a potential energy of 19J at the basket. How high is the ball from the floor?
3. A hockey puck has a potential energy of 2.3J when it is held by a referee at a height of 1.4 m above the rink surface. calculate the mass of puck?
My solutions:(used Eg=mgh to get all solutions)
1. a) 2.8J b) 0
2. h=31m
3. 0.6176 kg

I think you reversed the answers on 1.
2. mgh=19
h= 19/(.636*9.8) didn't you miss the decimal place?
3. mgh=PE
m= 2.3/(1.4*9.8) not your answer. 
when i divided 2.3/(1.4*9.8) i got 0.1676
and for quesiton 1 do u mean that a) will be 0J sinse it is rest on the desktop and b) will be 2.8 J 
yes, and yes.
Respond to this Question
Similar Questions

PHYSICS helppppp
A 0.2 kilogram baseball is thrown vertically downwards towards to the same horizontal floor. The baseball possesses an initial velocity of 30 meters per second. The height is 10.00m. (A) Calculate the POTENTIAL GRAVITATIONAL ENERGY … 
Physical Science
I need to know what equations to use! (A)How much work is done moving a 2.0Kg book to a shelf 2.00m high? 
physics
A book on a shelf 2.0 meters above the floor has a mass of 1.5 kilograms. What is the gravitational potential energy of the book? 
physics
1. You slowly lift a book of mass 2 kg at a constant velocity a distance of 3 m. How much work did you do on the book? 
physics
a book on a shelf 2.0 meters above the floor has a mas of 1.5 kilograms. what is the gravitational potential energy of the book. 
Physics
A 3.60 kg book is initially on a shelf located 1.80 m above the floor. The book is moved from the shelf to a coffee table that is just 0.380 m above the floor. What is the change in the book’s gravitational potential energy? 
Physics
A box of mass 4 kg is resting on a table 1.5 m above the floor. There is also a ledge located 5 m above the floor. Find the gravitational potential energy of the box relative to the floor, and the gravitational potential energy of … 
Physical SciencePhysics
You need to pick up a book off the floor and place it on a table top that is 0.78 m above ground. You expend 1.56 J of energy to lift the book. The book has an acceleration of 1.54 m/s squared. What is the book's mass? 
physics
I need so much help, thanks in advance! Determine the gravitational energy of your 3kg physics binder a) relative to the table it sits on b) relative to the floor, 0.68 meters below the book c) relative to the floor 2.5 meters above … 
Physics
A 1.55 m tall person lifts a 1.80 kg book off the ground so it is 1.95 m above the ground. A.) What is the potential energy of the book relative to the ground?