A projectile is launched at an angle of 19.0° above the horizontal. What is its initial speed if it hits a target that is located a horizontal distance of 175 m from the launch point and elevated 11.0 m from the launch level?

The initial speed of the projectile is 52.78 m/s

Explanation:

Applying equations of motion

The horizontal distance traveled by the projectile = R

R = u²sin2θ/g

where;

u is the initial speed of the projectile

g is acceleration due to gravity = 9.8

θ is the angle of projection = 19.0°

and given R = 175m

175 = u²sin2θ/g

175 = u²sin(2*19)/9.8

u²sin38⁰ = 1715

u² * 0.61566 = 1715

u²  = 1715/0.61566

u²  = 2785.628

u   = √2785.628

u   = 52.78 m/s

The initial speed of the projectile is 52.78 m/s

answer: option c. i.e. electric current flowing “downhill” from the negative electrode to the positive electrode in a battery

explanation:

the water analogy to the circuits define the pipes (water flows) to the electric current. now, we know that the electric current flows from the positive terminal to the circuit (as shown in the diagram attached).

hence, option c is the correct answer.