A pallet of bricks is to be suspended by attaching a rope to it and connecting the other end to a couple of heavy crates on the
roof of a building, as shown. The rope pulls horizontally on the lower crate, and the coefficient of static friction between the lower crate and the roof is 0.666. What is the weight of the heaviest pallet of bricks that can be supported this way?
A. 400 lb
B. 350 lb
C. 250 lb
D. 266 lb
A. 400 lb
B. 350 lb
C. 250 lb
D. 266 lb
1 answer:
You might be interested in
Answer:
A)
0.395 m
B)
2.4 m/s
Explanation:
A)
= mass of the cart = 1.4 kg
= spring constant of the spring = 50 Nm⁻¹
= initial position of spring from equilibrium position = 0.21 m
= initial speed of the cart = 2.0 ms⁻¹
= amplitude of the oscillation = ?
Using conservation of energy
Final spring energy = initial kinetic energy + initial spring energy
B)
= mass of the cart = 1.4 kg
= spring constant of the spring = 50 Nm⁻¹
= amplitude of the oscillation = 0.395 m
= maximum speed at the equilibrium position
Using conservation of energy
Kinetic energy at equilibrium position = maximum spring potential energy at extreme stretch of the spring
Answer:
t = 1.58 s
Explanation:
given,
Speed of ranger, v = 56 km/h
v = 56 x 0.278 = 15.57 m/s
distance, d = 65 m
deceleration,a = 3 m/s²
reaction time = ?
using stopping distance formula
t is the reaction time
t = 1.58 s
hence, the reaction time of the ranger is equal to 1.58 s.