Answer:
a)
b)
Explanation:
a) The displacement of the first object is 22.5 m, so we can use the next equation:
positive acceleration.
b) Using the same equation we can find the second value of the acceleration:
positive acceleration.
I hope it helps you!
Kinetic energy is related to velocity by:
KE = (1/2)mv^2
solve for mass m
10 = (1/2)m(10)^2
10 = (1/2)m(100)
10= 50m
10/50 = m
1/5 = m
at 20 km/hr
KE = (1/2)(1/5)(20)^2
KE = (1/10)(400)
KE = 40 J