Answer:
10m/s. C
Explanation:
Projectile motion is the motion of a body along a curved path
.there is a maximum height reached which the body stops moving temporarily.
Range is U^2sin2α/g
U= speed
g=acceleration due to gravity
α= angle if projection to
the horizontal
R= range( horizontal distance from the take off point) 8.5m
8.5=U^2*sin2(25°)/9.81
9.81*8.5=U^2*0.766
8.5*9.81/(Sin(50)=U^2
108.85=U^2
U=10.43318680083
U=10m/s. C
the speed which the boy lands is 10m/s