A volcano launches a lava bomb straight upward with an initial speed of 28m/s. Taking upward to be the positive direction, find speed and direction of motion of the lava bomb. a) 2.0seconds and b) 3.0seconds after it is launched

The equation to be used here would be:

v = u - gt

where u is the initial speed, g is the acceleration due to gravity and t is the time it takes

a) u = 28 m/s, g = 9.8 m/s^2, t = 2s

v = 28 m/s - 9.8 m/s^2 * 2s = 8.4 m/s after 2 s the lava bomb is still travelling upwards

b) u = 28 m/s g = 9.8 m/s^2 t = 3s

v = 28 m/s - 9.8 m/s^2 * 3s = - 1.4 m/s after 3s the lave bomb is travelling downwards