Answer:
48 hours
Explanation:
Using the formula,
R/R' = 2ᵃ/ᵇ..................... Equation 1
Where R = Original amount, R' = Radioactive remain, a = Total time, b = half life.
Given: b = 24 hours,
Let: R = X, then R' = X/4.
Substitute into equation 1
X/(X/4) = 2ᵃ/²⁴
4 = 2ᵃ/²⁴
2² = 2ᵃ/²⁴
Equating the base and solving for a
2 = a/24
a = 24×2
a = 48 hours.
Hence the time = 48 hours
Power = (voltage) x (current)
If the camcorder is USING 14 watts of electrical power right now, then . . .
14 watts = (2 volts) x (current)
Divide each side by (2 volts):
Current = (14 watts) / (2 volts)
Current = (14 V-A) / (2 V)
<em>Current = 7 Amperes</em>
Answer:
12 N
Explanation:
Use Newton's second law:
∑F = ma
F = (2.4 kg + 1.3 kg) (3.2 m/s²)
F = 11.84 N
Rounded to two significant figures, the force is 12 N.
Answer:
Potential energy = 1.6 J
Work done = -1.6 J
Explanation:
Potential Energy in the spring at this extension?
The potential energy U in the spring is U = 1/2kx² where k = spring constant = F/x where F = force = 20 N and x = extension = 0.16 m. So k = 20 N/0.16 m = 125 N/m
U = 1/2kx²
= 1/2 × 125 N/m × (0.16 m)²
= 1.6 J
What is the work done to extend the spring. 16 meters
Work done W = U₁ - U₂ where U₁ = initial potential energy = 0 and U₂ = final potential energy = 1.6 J
W = 0 - 1.6 J
= -1.6 J
Answer:
The metre is currently defined as the length of the path travelled by light in a vacuum in 1299 792 458 of a second
