Answer:
2.7
Explanation:
The following data were obtained from the question:
Mass (m) of box = 100 Kg
Length (L) of ramp = 4 m
Height (H) of ramp = 1.5 m
Mechanical advantage (MA) of ramp =?
Mechanical advantage of a ramp is simply defined as the ratio of the length of the ramp to the height of the ramp. Mathematically, it is given by:
Mechanical Advantage = Lenght / height
MA= L/H
With the above formula, we can obtain the mechanical advantage of the ramp as follow:
Length (L) of ramp = 4 m
Height (H) of ramp = 1.5 m
Mechanical advantage (MA) of ramp =?
MA = 4/1.5
MA = 2.7
Therefore, the mechanical advantage of the ramp is 2.7
The radius, r, of the child from the center of the wheel is
r = 1.3 m
The wheel makes one revolution in 4.2 s. Its angular velocity is
ω = (2π rad)/(4.2 s) = 1.496 rad/s
The linear speed of the child is the tangential velocity, given by
v = rω
= (1.3 m)*(1.496 rad/s)
= 1.945 m/s
Answer: 1.95 m/s (nearest hundredth)
North to north repels, south to south repels, north to south attracts, the same vise versa.