Question

1. The North American and European continents are moving apart at a rate of about 3 cm/y. At this how long will it take them to drift 800km farther apart than they are at present?

2. Assume air resistance is negligible unless otherwise stated. A coin is dropped from a hot-air balloon that is 250 m above the ground and rising at 12.0 m/s upward. For the coin, find the following.

a) the maximum height (in m) reached

b) its position and velocity (in m and m/s, respectively) 5.00 s after being released (Assume that the +x-axis is to the right and the +y-axis is up along the page. Indicate the direction with the sign of your answer.)

c) the time (in s) before it hits the ground

Answer 1

Only one question can be posted as per HomeworkLib guidelines.

1.

Given speed of continent moving

V=3 cm/y =0.03 m/y

Time taken by the continent to drift 800 km is

t =d/V =(800*10³)/(0.03)=2.6667*10⁷ years.

2.

a)

From Kinematic equation

V_fy²=V_oy²-2g(y-y_o)

At maximum height V_fy=0

0=12²-2*9.8(H_max-250)

H_max=(144/19.6)+250 =257.3 m

b)

from

Y=Y_o+V_oyt-(1/2)gt²

at t=5 s

Y=250+12*5-(1/2)*9.8*5²

Y=187.5 m

From

V_fy=V_oy-gt

V_fy=12-9.8*5

V_fy=-37 m/s

c)

from

Y=Y_o+V_oyt-(1/2)gt²

when balloon hits the ground y=0

0=250+12t-(1/2)(9.8)t²

4.9t²-12t-250=0

t=8.47 s