A rugby player passes the ball 6.8 m across the field, where the ball is caught at the same height as it left his hand. show answer No Attempt 33% Part (a) At what angle, in degrees above the horizontal, was the ball thrown if its initial speed was 12.0 m/s, assuming that the smaller of the two possible angles was used

11.86°

Explanation:

Projectile motion is a form of motion where an object moves in parabolic path (trajectory). Projectile motion only occurs when there is one force applied at the beginning on the trajectory, after which the only interference is from gravity.

The range of an object experiencing projectile motion is given by:

R = u²sin(2θ) / g

where u is the initial velocity, θ is the angle with horizontal and g is the acceleration due to gravity

Given that R = 6.8 m, g = 10 m/s², u = 12 m/s.  

R = u²sin(2θ) / g

substituting:

6.8 = 13²sin(2θ) / 10

13²sin(2θ) = 68

sin(2θ) = 0.4024

2θ = sin⁻¹(0.4024)

2θ = 23.73

θ = 11.86°

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.