After a cannonball is fired into frictionless space, the amount of force needed to keep it going equals
a zero, since no force is necessary to keep it moving.
b twice the force with which it was fired.
c one half the force with which it was fired.
d the same amount of force with which it was fired.
e one quarter the force with which it was fired.

A zero, since no force is necessary to keep it moving

Step-by-step explanation:

Since, the space is friction less, the force exerted by the gun will be enough to  keep the ball going. There will not be any depreciation in the initial force. Hence, the ball continues to move forward without any impediment.

Hence, the correct answer is

A zero, since no force is necessary to keep it moving

10 cm

step-by-step explanation:

if the polygon is a rectangle, then the perimeter is x+x+y+y. using the values that you gave, the perimeter is 3+3+2+2=10cm.

total amount to be paid = $19.5

step-by-step explanation:

given ,

original price = $25.99

discount = 25%

discount amount = 25% of original price

discount amount = 25/100   * 25.99

discount amount = $6.49

hence , the total amount to be paid = original price - discount amount

                                                            = $25.99 - $6.49

                                                            =$19.5

total amount to be paid = $19.5