#"a-"#
- the force compressing the spring is the weight of stone of mass of 8 kilogram.
- The weight of the stone creates a backward force on the spring.
- we can calculate the recall force using the following formula.
#F=-K*Delta x#
#"where K is spring constant, " Delta x=10 cm=0.1 m#
#F=G=m*g" where G is the weight of the stone."#
#F=G=8*9.81=78.48N#
#78.48=K*0.1#
#K=(78.48)/(0.1)=784.8=7.85*10^2" "N/m#
#"b-"#
#"(i)"#
#"total amount of compressing:10+30=40 cm=0.4 m"#
#"Energy stored in the spring can be calculated using :"#
#E=1/2*K*(Delta x)^2#
#E=1/2* 785*(0.4)^2=1/2*785*0.16=62.8J#
#(ii)#
#"Deposited on the spring energy is transferred to the stone"#
#"The stone gains kinetic energy and rises from the ground...."#
#"When the stone reaches its maximum height, the kinetic "#
#"energy becomes zero."#
#"The total energy of the stone at maximum height is only"#
#"potential energy."#
#E_p=m*g*h#
#"where h is maximum height."#
#62.8=8*9.81.h#
#h=(62.8)/(8.9.81)#
#h=0.80 m#