Question #1c2bd
1 Answer
Explanation:
Before the force is applied we know
#"momentum" = "mass" times "velocity" = "10 kg m/s"#
Since mass in the above is
We can now work out kinetic energy, KE:
#KE=1/2mv^2=1/2*5*2^2="10 J"#
The force of
#F=(mv-"mu")/t=m * (v-u)/t#
Where
So
#0.2 = 5 * ((v-2))/10#
rearranging helps us find
#2 = 5 * (v-2)#
#2/5 = v-2#
#v = 12/5" ms"^(-1)#
Hence final kinetic energy,
#KE = 1/2mv^2 = 1/2 * 5 * (12/5)^2 = "14.4 J"#
So the overall change in
#Delta_"KE" = 14.4 - 10 = "4.4 J"#