Answer:
accleraion normal ski 0.0735 m/s², new ski 0.219 m/s²
Explanation:
This exercise should work with the one-dimensional kinetic equations, specifically with the equation
x = v₀ t + ½ a t²
When the skier is at the exit they are at rest, so their initial speed is zero
(v₀ = 0)
x = ½ a t²
Let's calculate the acceleration for normal skiing
a₁ = 2 x / t²
a₁ = 2 175/69²
a₁ = 0.0735 m/s²
a₁ = 7.35 10⁻² m/s²
Let's calculate the acceleration with the new plastic ski
a₂ = 2 x / t₂²
a₂ = 2 175/40²
a₂ = 0.219 m/s²
a₂= 2.19 10⁻¹ m/s²
Answer:
A = 0.325 Bq
Explanation:
given,
half life of ¹⁴C = 5730 years
fixed fraction 1.30 × 10⁻¹² of ¹²C
half life = 5730 years
T_{1/2} = 5730 x 365 x 24 x 60 x 60
= 1.807 x 10¹¹ s
radioactive decay constant
λ =
λ =
λ = 3.835 x 10⁻¹² /s
number of atom
mass m = 1.30 g
n = 6.524 x 10²²
Number of ¹⁴C atoms in 1.3 g of sample N ' =
= 1.30 × 10⁻¹² x 6.524 x 10²²
= 8.482 x 10¹⁰
Required activity, A = λ N
A = 3.835 x 10⁻¹² x 8.482 x 10¹⁰
A = 0.325 Bq
Do not use water on chemical fires such as magnesium, or on electrical fires.
Balance them that's the reason why
1. the max height is solved from v = square root of 2 gy where g is equal to 9.8 m/s2/ hence y is equal to 8.62 meters.
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2. time at max height is solve when velocity = 0. ( 0 = -9.81*t +13); t = 1.325 seconds
3. time required for the entire trip is 2*1.325 equal to 2.65 seconds.
4. without air resistance, the velocity just before the ball hits the ground is the same as its initial velocity, 13 m/s.</span>