Objects should be cooled before their mass is determined on a sensitive balance because it could damage the balance. Also, because it would give you wrong reading of the mass. Hot objects would warm the air around it. A warm air would expand and would produce convection as it rises causing to give the object a mass that is less than the actual. Another reason would be it would cause instability in the readings, the mass would fluctuate every now and then due to the convection currents around the object. It is always recommended to weigh the masses of objects that are in room temperature.
Answer:
a) I = 2279.5 N s
, b) F = 3.80 10⁵ N, c) I = 3125.5 N s and d) F = 5.21 10⁵ N
Explanation:
The impulse is equal to the variation in the amount of movement.
I =∫ F dt = Δp
I = m
- m v₀
Let's calculate the final speed using kinematics, as the cable breaks the initial speed is zero
² = V₀² - 2g y
² = 0 - 2 9.8 30.0
= √588
= 24.25 m/s
a) We calculate the impulse
I = 94 24.25 - 0
I = 2279.5 N s
b) Let's join the other expression of the impulse to calculate the average force
I = F t
F = I / t
F = 2279.5 / 6 10⁻³
F = 3.80 10⁵ N
just before the crash the passenger jumps up with v = 8 m / s, let's take the moments of interest just when the elevator arrives with a speed of 24.25m/s down and as an end point the jump up to vf = 8 m / n
c) I = m - m v₀
I = 94 8 - 94 (-24.25)
I = 3125.5 N s
d) F = I / t
F = 3125.5 / 6 10⁻³
F = 5.21 10⁵ N
Answer:
The height of the platform is 22.686 m.
Explanation:
Given;
initial velocity of Janet, u = 2.63 m/s
time of her motion, t = 1.9 s
The height of the platform is given by;
h = ut + ¹/₂gt²
substitute the given values and solve for height "h"
h = (2.63 x 1.9) + ¹/₂(9.8)(1.9)²
h = 4.997 + 17.689
h = 22.686 m
Therefore, the height of the platform is 22.686 m.
Answer:a) 20.944rad/s (b) 12.57m/s (c) 800rev/min²
Explanation:
The final velocity of object 2 is: 3 m/sec
<h3>What is the conservation of mass?</h3>
According to the rule of conservation of mass, no atoms are created or destroyed during a chemical process. Instead, the atoms combine in a variety of ways to create goods. This explains why each element has the equal amount of atoms on both sides of an equation with balanced symbols.
According to conservation of mass,
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
Given that,
m₁ = 50 kg
m₂ = 75 kg
u₁ = 4 m/s
u₂ = -1 m/s
v₁ = -2 m/s
v₂ = ?
Now, putting the values,
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
(50 × 4) + [75 × (-1)] = [50 × (-2)] + (75 × v₂)
or, 125 = -100 + 75 v₂
or, 75 v₂ = 225
or, v₂ = 3 m/sec.
To know more about velocity refer to:
brainly.com/question/80295
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