A cannonball is fired horizontally at 10 m/s from a cliff. Its speed one second after being fired is about

A. 10m/s

B. 12m/s

C. 14m/s

D. 16m/s

E. 20m/s

F. 22m/s

###### Answer. Posted on Saturday, January 31, 2015.

The vertical component of the velocity increases in the downward direction.

According the following formula Vf=Vi+g*t , After 1s, the vertical component of the velocity will be 9.8 m/s.

The horizontal component of the velocity remains unchanged 10 m/s.

The velocity can be calculated by the formula V = √(Vx^2+Vy^2) , where Vx – the horizontal component of the velocity and Vy – the vertical component of the velocity.

Finally, V = √ (10^2+9.8^2) = 14 m/s.

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