March 7, 2018 Phys 213 Quiz 2 Fall 2018 Answer all the questions 1. An elevator
ID: 2268916 • Letter: M
Question
March 7, 2018 Phys 213 Quiz 2 Fall 2018 Answer all the questions 1. An elevator whose mass is 2000 kg is moving upward. It's speed is increasing at the rate of 2. A ramp is elevated at an angle of 45*. A 10 kg mass is pulled up on the ramp, by a rope at an 3. A 2 kg particle moves along x axis according to x(t)- 2+3t +4t+t, where x is in meters and t is 2m/s. What is the tension in the rope? acceleration of 2 m/s. The coefficient of kinetic friction is 0.4. What is the tension in the rope? in seconds, what is the net force acting on it at t = 2 s?Explanation / Answer
1. Fnet = T - m g = m a
T = m (a + g) = 2000 (9.8 + 2)
T = 23600 N
2. T - m g sin45 - fk = m a
fk = uk N = uk m g cos45
T - m g sin45 - uk m g cos45 = m a
T = 10 (2 + 9.8(sin45 + 0.4cos45))
T = 194 N
3. v = dx/dt = 3 + 8 t + 3 t^2
a = dv/dt = 8 + 6 t
t= 2 s, a = 8 + 12 = 20 m/s^2
Fnet = m a = 2 x 20 = 40 N