PLZ HELP I REALLY NEED THIS NOW????????


Directions: For each situation, you need to determine if the object has KE or GPE or both. Then find their values. Be sure to include the correct units.

1. A 2-kg bowling ball sits on top of a building that is 40 meters tall.

Circle one: KE / GPE / both

Show your work for finding the values of each type of energy the object has:




2. A 2-kg bowling ball rolls at a speed of 5 m/s on the roof of the building that is 40 tall.

Circle one: KE / GPE / both

Show your work for finding the values of each type of energy the object has:



3. A 2-kg bowling ball rolls at a speed of 10 m/s on the ground.

Circle one: KE / GPE / both

Show your work for finding the values of each type of energy the object has:



4. A 20-kg child is tossed up into the air by her parent. The child is 2 meters off the ground traveling 5 m/s.

Circle one: KE / GPE / both

Show your work for finding the values of each type of energy the object has:













Part 2: Finding Speed and Height Using Energy

Directions: Use the KE and GPE equations to solve for speed or height depending on the situation.

1. A 1,000-kg car has 50,000 joules of kinetic energy. What is its speed?


2. A 200-kg boulder has 39,200 joules of gravitational potential energy. What height is it at?


3. A 1-kg model airplane has 12.5 joules of kinetic energy and 98 joules of gravitational potential energy. What is its speed? What is its height?


Respuesta :

1. A 2-kg bowling ball sits on top of a building that is 40 meters tall. Circle one: KE / GPE / both Show your work for finding the values of each type of energy the object has:

KE = 0 (because velocity is 0)

PE = mgh = 2kg*9.8m/s^2*40m= 784 joule

2. A 2-kg bowling ball rolls at a speed of 5 m/s on the roof of the building that is 40 tall. Circle one: KE / GPE / both Show your work for finding the values of each type of energy the object has:

Both
KE = [1/2]m*v^2 = [1/2](2kg)(5m/s)^2 =  25 joul
PE = mgh = 40 joule

3. A 2-kg bowling ball rolls at a speed of 10 m/s on the ground. Circle one: KE / GPE / both Show your work for finding the values of each type of energy the object has: 

KE = [1/2]m(v^2) = [1/2]2kg*(10m/s)^2 = 100 joule

GPE = mgh = 0

1. A 1,000-kg car has 50,000 joules of kinetic energy. What is its speed?

KE = [1/2]m(v^2) => v = √[2KE/m] = √[2*50,000joules/1000kg] = 10m/s

2. A 200-kg boulder has 39,200 joules of gravitational potential energy. What height is it at? 

GPE = mgh => h = GPE / (mg) = 39,200 joules / (200kg * 9.8m/s^2) = 20m


3. A 1-kg model airplane has 12.5 joules of kinetic energy and 98 joules of gravitational potential energy. What is its speed? What is its height?

KE = [1/2]m(v^2) => v = √ [ 2KE/m] = √[2*12.5 j / 1kg] = 5 m/s

GPE = mgh => h = GPE/(mg) = 98/(1kg*9.8m/s^2) = 10 m

Sorry I don't know number 4 for part 1