A .300kg bullet is fired from a gun at a speed of 747km/h. If the bullet rises straight up into the air, what is the maximum height that the bullet can reach?
2006-11-06 04:19:41 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Engineering
The bullet rises until all its kinetic energy is converted to potential energy.
Its kinetic energy at start is (1/2)mv^2 = (1/2)*300*(747*5/18)^2. Here the 5/18 term is the conversion factor from kmph to metres per second.
When it reaches the top most point 'h', its potential energy will be mgh
Thus (1/2)mv^2 = mgh
Therefore, h=v^2/(2g) = (747*5/18)^2 / 2*9.81 = 2194metres = 2.194kms
2006-11-06 04:41:50 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Sssuming g constant,
0 - Vi^2 = -2gh
h = (((747 km/hr)(1 hr.3600 sec))^2)/(2*0.00980662 km/sec^2)
h = 2.195 km
1 - (6378.137/6380.332) = 0.0007, so the assumption of constant g is workable.
2006-11-06 15:46:02 · answer #2 · answered by Helmut 7 · 0⤊ 0⤋