A car starts from rest and accelerates uniformly over a time of 7 seconds for a distance of 190m. Find the the acceleration of t
1 answer:
Answer:
a = 7.75 [m/²]
Explanation:
To solve this problem we must use the following equation of kinematics.
where:
x = final distance = 190 [m]
Xo = initial distance = 0
Vo = initial velocity = 0 (car starts from the rest)
a = acceleration [m/s²]
t = time = 7 [s]
190 = 0 + (0*7) + 0.5*a*(7²)
190 = 0.5*49*a
a = 7.75 [m/²]
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Answer:
a) 0.0007326
b) 0.03223
c) 0.2418
d) 0.2418
Explanation:
To find different probabilities for the selection of components among eleven good and four defective components, we will use the Combination.
a)
b)
c)
d)
Answer:
block velocity v = 0.09186 = 9.18 10⁻² m/s and speed bollet v₀ = 11.5 m / s
Explanation:
We will solve this problem using the concepts of the moment, let's try a system formed by the two bodies, the bullet and the block; In this system all scaffolds during the crash are internal, consequently, the moment is preserved.
Let's write the moment in two moments before the crash and after the crash, let's call the mass of the bullet (m) and the mass of the Block (M)
Before the crash
p₀ = m v₀ + 0
After the crash
= (m + M) v
p₀ =
m v₀ = (m + M) v (1)
Now let's lock after the two bodies are joined, in this case the mechanical energy is conserved, write it in two moments after the crash and when you have the maximum compression of the spring
Initial
Em₀ = K = ½ m v2
Final
E = Ke = ½ k x2
Emo = E
½ m v² = ½ k x²
v² = k/m x²
Let's look for the spring constant (k), with Hook's law
F = -k x
k = -F / x
k = - 0.75 / -0.25
k = 3 N / m
Let's calculate the speed
v = √(k/m) x
v = √ (3/8.00) 0.15
v = 0.09186 = 9.18 10⁻² m/s
This is the spped of the block plus bullet rsystem right after the crash
We substitute calculate in equation (1)
m v₀ = (m + M) v
v₀ = v (m + M) / m
v₀ = 0.09186 (0.008 + 0.992) /0.008
v₀ = 11.5 m / s