For purposes of completing our calculations, we're going to assume that
the experiment takes place on or near the surface of the Earth.
The acceleration of gravity on Earth is about 9.8 m/s², directed toward the
center of the planet. That means that the downward speed of a falling object
increases by 9.8 m/s for every second that it falls.
3 seconds after being dropped, a stone is falling at (3 x 9.8) = 29.4 m/s.
That's the vertical component of its velocity. The horizontal component is
the same as it was at the instant of the drop, provided there is no horizontal
force on the stone during its fall.
I guess the correct answer is the first one.
The answer is C. friction, acting in opposition to the motion of the ball
Answer:
Yes, a force is require to set an object in motion.
Explanation:
- In space, even if you feel weightless, you are subject to motion. If you are orbiting the Earth, you are under the constant influence of Earth having a free-fall acceleration equal to the centripetal acceleration.
- To disturb this orbital motion, an external force is required.
- According to Newton's laws of motion, a force is required to change the state of the rest of a body or to change the velocity or direction if it is moving with uniform velocity along a straight line.
- Whenever there is a change in velocity or direction of a body there is a force acting on it.
