## 4. A cinder block is sitting on a platform 20 m high. It weighs 79 N. The block has _____________ energy. Calculate it. 5. There is a bell at the top of a tower that is 45 m high. The bell weighs 190 N. The bell has ____________ energy. Calculate it. 6. A roller coaster is at the top of a 72 m hill and weighs 966 N. The coaster (at this moment) has ____________ energy. Calculate it. PLZZ HELPPPP

October 12, 2019// Blog//

Kinetic energy = 0.5*M*V^2

Q7-

0.5*3*(2^2)= 6J

Q8a-

0.5*2*(2^2)= 4J

0.5*4*(3^2)=18J

the second ball has more kinetic energy.

Q8b-

at the max height, all the kinetic energy is converted to potential energy,

gravitational potential energy is = M*g*h

that theory would apply if you wanted to work out the maximum height achieved if the balls were thrown upward by rearranging. But, we are simply working out which ball will have more potential energy so:

First ball:

2kg*9.81(g)*10m = 196.2J

Second ball

4kg*9.81*10m= 392.4J

The second ball has more potential energy