A high-speed dart is shot from ground level with a speed of 150 m/s at an angle 30° above the horizontal. What is the vertical component of its velocity after 4.0 s if air resistance is neglected?

Explanation:

The dart is project with 150 m/s from a point at an angle of 30⁰

The vertical component of velocity = 150 sin 30 = 75 m/s

Thus initial vertical velocity is = 75 m/s

The velocity after 4 s can be calculate by

v = u - g t

here u is the initial velocity and t is the time , g is the acceleration due to gravity .

Thus v = 75 - 10 x 4 = 35 m/s

a small object of mass 3.66 g and charge -17.6 µc is suspended motionless above the ground when immersed in a uniform electric field perpendicular to the ground. what are the magnitude and direction of the electric field?

coil wire, increase current, put iron inside the coil