A projectile is fired from ground level on a horizontal plain.If the initial speed of the projectile is now doubled,and we neglect air resistance,
A)its range will be increased by .
B)its range will double.
C)its range will be decreased by a factor of two.
D)its range will quadruple.
E)its range will decrease by a factor of four.

Question

A projectile is fired from ground level on a horizontal plain.If the initial speed of the projectile is now doubled,and we neglect air resistance,
A)its range will be increased by . 
B)its range will double. 
C)its range will be decreased by a factor of two. 
D)its range will quadruple. 
E)its range will decrease by a factor of four.

Quizplus · Accepted Answer

The range of a projectile with initial speed v and launch angle θ is given by R = v²sin(2θ)/g, where g is the acceleration due to gravity. If the initial speed is doubled, the new range is R' = (2v)²sin(2θ)/g = 4(v²sin(2θ)/g) = 4R. Therefore, the range quadruples.

A Projectile Is Fired from Ground Level on a Horizontal