After the ice storm, you decide to check on your friend who lives at the top of
ID: 1528916 • Letter: A
Question
After the ice storm, you decide to check on your friend who lives at the top of a hill with an incline of 30 degrees. Due to the ice, your car won't make it up the 105-meter road to her house. With the aid of metal toe cleats, even with ice covering the road, you manage to walk up the hill at 1/2 m/s. When you are 5 meters from the top you lose your toe cleats and start sliding. Assume your mass is 50 kg. What is your acceleration as you slide down the ice-covered road? What is your initial momentum, the instant you slip? How much time does it take you to get back to the bottom of the hill? What is your velocity when you reach the bottom of the hill? What is your momentum the instant you reach the bottom of the hill?Explanation / Answer
a) a = g*sin(theta)
= 9.8*sin(30)
= 4.9 m/s^2
b) Initial momentum = 0
c) let t is the time taken.
use, s = u*t + (1/2)*a*t^2
s = 0 + (1/2)*a*t^2
==> t = sqrt(2*s/a)
= sqrt(2*105/4.9)
= 6.55 s
d) use, v = u + a*t
= 0 + 4.9*6.55
= 32.1 m/s
e) final momentum = m*v
= 50*32.1
= 1605 kg.m/s