Answer:
1.8 s
Explanation:
Potential energy = kinetic energy + rotational energy
mgh = ½ mv² + ½ Iω²
For a thin spherical shell, I = ⅔ mr².
mgh = ½ mv² + ½ (⅔ mr²) ω²
mgh = ½ mv² + ⅓ mr²ω²
For rolling without slipping, v = ωr.
mgh = ½ mv² + ⅓ mv²
mgh = ⅚ mv²
gh = ⅚ v²
v = √(1.2gh)
v = √(1.2 × 9.81 m/s² × 4.8 m sin 39.4°)
v = 5.47 m/s
The acceleration down the incline is constant, so given:
Δx = 4.8 m
v₀ = 0 m/s
v = 5.47 m/s
Find: t
Δx = ½ (v + v₀) t
t = 2Δx / (v + v₀)
t = 2 (4.8 m) / (5.47 m/s + 0 m/s)
t = 1.76 s
Rounding to two significant figures, it takes 1.8 seconds.
Answer:
73.72
Explanation:
For this subtraction problem, the answer or solution is expressed to the least precise of the numbers we are trying to subtract.
The least precise number is the number with the lowest significant numbers:
105.4 - 31.681
105.4 has 4 significant numbers
31.681 has 5 significant numbers
So;
105.4
- 31.681
------------------
73.719
----------------
The solution is therefore 73.72
Answer:
-0.4 m/s
Explanation:
According to the law of conservation of momentum, the total momentum of the bullet - rifle system must be conserved.
The total momentum before the shot is zero, since they are both at rest:
While the total momentum after the shot can be written as:
where
m = 10 g = 0.010 kg is the mass of the bullet
M = 5 kg is the mass of the rifle
v = 200 m/s is the velocity of the bullet
V is the recoil velocity of the rifle
Since the total momentum is conserved, we can write:
So
And solving for V, we find the recoil velocity:
and the negative sign indicates that the velocity is opposite to the bullet.
Frequency of the wave is 2 per second
Explanation:
- Frequency is the number of times waves pass at a particular point of time. Here, time period = 0.5 s
- Frequency is given by the formula
f = 1/T, where f is the frequency and T is the time period
⇒ f = 1/0.5 = 2 per second
C partial solar eclipse are formed
