Answer:
55738.539 Pa
Explanation:
Gvien:
The mass of the man = 73 kg
Mass of the chair = 7.4 kg
radius of the leg of the chair = 1.5 cm = 0.015 m
Now,
the force of gravity due to both the masses, F = (73+7.4) kg x 9.8 = 787.92 N
Also,
Pressure = force / area
Area of a circle of leg = πr² = π x 0.015² = 7.068 x10⁻⁴ m2
Now,
there are 2 legs so the force will be divided evenly in each leg
thus,
F' =
Hence, the pressure on each leg will be
Pressure =
(a) The block has a weight of (27.0 kg) <em>g</em>, and the normal force of the surface pushing upward on the block has the same magnitude, so that static friction exerts a maximum force of
<em>µ</em> (27.0 kg) <em>g</em> = 70.0 N
where <em>µ</em> is the coefficient of <u>static</u> friction. Solving for <em>µ</em> gives
<em>µ</em> = (70.0 N) / ((27.0 kg) <em>g</em>) ≈ 0.265
(b) As it's moving, the block still has the same weight and thus feels the same normal force, (27.0 kg) <em>g</em>. In order to move at a constant speed, kinetic friction must exert the same force as the push, so
<em>µ</em> (27.0 kg) <em>g</em> = 64.0 N
where <em>µ</em> is now the coefficient of <u>kinetic</u> friction. Solve for <em>µ</em> :
<em>µ</em> = (64.0 N) / ((27.0 kg) <em>g</em>) ≈ 0.242
D) chemical change, irreversible.
This is because if two liquids made a solid when mixed together, it was most likely a chemical change (especially is bubbles were produced!), and a chemical change is permanent!
Answer:
32.66 m/s
Explanation:
The potential energy stored in the spring will impart kinetic energy into the dart:
substitute the values: