d = distance traveled by her on her bicycle on a long flat road = 24 kilometer
t = time taken by her to travel distance "d" on her bicycle on a long flat road = 1.2 hours
v = average speed of vivian = ?
we know that average speed is given as
v = d/t
inserting the values in the above formula
v = 24 kilometer / 1.2 hour
v = 20 kilometer/hour
hence the correct choice is
C) 20 km/h
C) total linear momentum of the ball and cannon is conserved.
Basically it happens that in the beginning before there is a momentum acting on the two bodies, these are a unique system. Here the total momentum of the System is 0. However, when the positive momentum of the cannonball is added, the system will be immediately affected by a negative momentum which will pull back the cannon. Could this be extrapolated as a condition of Newton's third law.
<span>(20 cm)/(5 sec) = (0.20 meters)/(5 seconds)
</span>
the answer might be 2.3 kilos
