Galileo, in his book Two new sciences, stated that for elevations that exceed or fall short of 45° by equal amounts, the ranges?
1. are equal to each other.
2. are not equal to each other.
3. are sometimes equal and sometimes are not equal to each other.
4. it depends on the difference between the angles.
A hiker stands on the edge of a cliff 490 m above the ground and throws a stone horizontally with an initial speed of 15 m/s. Neglecting air resistance, the time taken by the stone to reach the ground and the speed with which it hits the ground are, respectively: (Take g = 9.8 ).
1. 10 s & 99 m/s
2. 10 s & 15 m/s
3. 5 s & 99 m/s
4. 5 s & 15 m/s
A cricket ball is thrown at a speed of 28 m/s in a direction 30° above the horizontal. The time taken by the ball to return to the same level is:
|1.||2.5 s||2.||2.9 s|
|3.||3.5 s||4.||3 s|
A cricket ball is thrown at a speed of 28 m/s in a direction 30° above the horizontal. The maximum height attained by the ball is:
1. 5 m
2. 10 m
3. 15 m
4. 20 m