1. A bullet of mass 10 g is fired vertically upward and it reaches to the highest point in 10 seconds. Which of the following figures is nearer to its maximum height above the firing position?
A) 10 m
B) 22 m
C) 30 m
D) 42 m
E) None of the above
h = 0.5g*t^2 = 4.9*10^2 = 490 m.
No
22
To determine the maximum height reached by the bullet, we can use the kinematic equation for vertical motion:
y = v0*t - (1/2)*g*t^2
where:
y = vertical displacement (maximum height)
v0 = initial velocity
t = time
g = acceleration due to gravity
Given that the bullet reaches its maximum height in 10 seconds, we can plug in the values:
y = 0*t - (1/2)*g*t^2
Since the bullet is fired vertically upward, the initial velocity is positive (upward), so we can ignore the v0*t term.
y = -(1/2)*g*t^2
To determine which option is closest to the maximum height, we need to calculate the value of y. Note that the value of g is approximately 9.8 m/s^2.
For option A) 10 m:
y = -(1/2)*9.8*(10^2) = -490 m
For option B) 22 m:
y = -(1/2)*9.8*(10^2) = -490 m
For option C) 30 m:
y = -(1/2)*9.8*(10^2) = -490 m
For option D) 42 m:
y = -(1/2)*9.8*(10^2) = -490 m
Since all the options have the same calculation result, none of the above options (E) are the correct answer.