A new interstate highway is being built with a design speed of 120 km/h. For one of the horizontal curves, the radius (measured
1 answer:
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Answer:
0.799 m/s if air resistance is negligible.
Explanation:
For how long is the ball in the air?
Acceleration is constant. The change in the ball's height depends on the square of the time:
,
where
is the change in the ball's height.
is the acceleration due to gravity.
is the time for which the ball is in the air.
is the initial vertical velocity of the ball.
- The height of the ball decreases, so this value should be the opposite of the height of the table relative to the ground.
.
- Gravity pulls objects toward the earth, so
near the surface of the earth.
- Assume that the table is flat. The vertical velocity of the ball will be zero until it falls off the edge. As a result,
.
Solve for .
;
;
;
.
What's the initial horizontal velocity of the ball?
- Horizontal displacement of the ball:
;
- Time taken:
Assume that air resistance is negligible. Only gravity is acting on the ball when it falls from the tabletop. The horizontal velocity of the ball will not change while the ball is in the air. In other words, the ball will move away from the table at the same speed at which it rolls towards the edge.
.
Both values from the question come with 3 significant figures. Keep more significant figures than that during the calculation and round the final result to the same number of significant figures.