We need to be careful here.
The calculation of the gravitational force between two objects
refers to the distance between their centers.
The minimum possible distance between the Earth's and moon's
centers is the sum of their radii (radiuses).
Earth's radius . . . . . 6,360 km = 6.36 x 10⁶ meters
Moon's radius . . . . . 1,738 km = 1.738 x 10⁶ meters
Sum of their radii = 8.098 x 10⁶ meters
Also:
Earth's mass . . . . . 5.972 x 10²⁴ kg
Moon's mass . . . . . 7.348 x 10²² kg
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and now we're ready to go !
Gravitational force =
G M₁ M₂ / R²
= (6.67 x 10⁻¹¹ N-m²/kg²)(</span><span>5.972 x 10²⁴ kg)(7.348 x 10²² kg)/</span>(8.098 x 10⁶ m)²
= (6.67 · 5.972 · 7.348 / 8.098²) · (10²³) Newtons
= (I get ...) 4.463 x 10²³ Newtons
That's almost exactly 10²³ pounds
= 50,153,000,000,000,000,000 tons.
Those are big numbers.
All I can say is: I wouldn't exactly call that "resting" on the surface".
Answer
given,
initial speed of hockey player= 0 m/s
mass of the helmet, m = 1.3 Kg
initial speed of the helmet, u = 0 m/s
final speed of the helmet, v = 6 m/s
recoil speed of the hockey player, v' = 0.25 m/s
we need to calculate the mass of the hockey player, M = ?
using conservation of momentum
m u + M u' = M v' + m v
initial speed of ice skater is zero
1.3 x 0 + M x 0 = M x (-0.25) + 1.3 x 6
negative sign is taken because recoil velocity is in opposite direction
0 = -0.25 M + 7.8
0.25 M = 7.8
M = 31.2 Kg
Hence, the mass of the young hockey player is equal to 31.2 Kg
No it can't it's material
Answer: false
Explanation:
You have to make sure it doesn’t stay wet
Answer:
525 Bq
Explanation:
The decay rate is directly proportional to the amount of radioisotope, so we can use the half-life equation:
A = A₀ (½)^(t / T)
A is the final amount
A₀ is the initial amount,
t is the time,
T is the half life
A = (8400 Bq) (½)^(18.0 min / 4.50 min)
A = (8400 Bq) (½)^4
A = (8400 Bq) (1/16)
A = 525 Bq
