Answer:
(a) 1.11 m
(b) 4760 kgm/s
Explanation:
height of plane (h) = 370 m
velocity (v) = 56 m/s
mass (m) = 85 kg
force = 1.2 x 10^{5} N = 120,000 N
(a) We can get the minimum depth of snow from the equation below
force x depth = kinetic energy on impact
f x d = 0.5 x m x v^{2}
120000 x d = 0.5 x 85 x 56^{2}
d= (0.5 x 85 x 56^{2}) ÷ 120000 = 1.11 m
(b) the magnitude of impulse is equal to the momentum of the paratrooper and his gear
= m x v
= 85 x 56 = 4760 kgm/s
If you dropped a ball from any height, and measured its distance from the ground at any regular interval while it's falling, the graph of that distance versus time would be a graph that curves downward.
-- The ball is falling down. As time goes on, it gets closer and closer to the ground. Its remaining distance from the ground keeps decreasing, so the line on the graph slopes down.
-- The speed of the ball keeps increasing (it accelerates) because of the gravitational force on it. As time goes on, it covers more of the remaining distance during each interval than it did in the previous interval. The downward slope of the graph keeps increasing.
If the statistical analysis shows that the significance level is below the cut off value they have set (either 0.05 or 0.01) they reject the null hypothesis and accept the alternative hypothesis
Assuming north as positive direction, the initial and final velocities of the ball are:
(with negative sign since it is due south)
the time taken is
, so the average acceleration of the ball is given by
And the positive sign tells us the direction of the acceleration is north.
