Answer:
d) v1 = v2 = v3
Explanation:
This can be answered using conservation of energy. We calculate the mechanical energy E=K+U (sum of kinetic and gravitational potential energies) at the original and final points, and impose they are equal.
At the original point we have, for the three balls:
At the final point we have, for the three balls:
Since we have 
, and 
is the same for all balls, then 
is the same for all balls, which means that 
, the final velocity, is the same for all balls.
Answer:
the motorcycle travels 42.4 meters until it stops.
Explanation:
Vi= 18 m/s
Vf= 0 m/s
t= 4.7 sec
Vf= Vi - a*t
deceleration:
a= Vi/t
a= 18m/s / 4.7 sec => a=-3.82 m/s²
x= Vi*t - (a * t²)/2
x= 42.4m
(a)
The work done on the projectile is 9375 joule.
The work on the projectile is calculated as
W=F×d
=1250×7.5
=9375 joule
(b)
The speed of the projectile after 7.5 m is 27.38 m/s
First we need to find out the acceleration of the projectile
F=m×a
1250=25×a
a=50 m/
Now the velocity of the projectile after 7.5 m is calculated as
v^2=u^2+2a×s
v^2=0+2×50*7.5
v=27.38 m/s
