v = u + at where v = final speed, u = initial speed , a = acceleration and t = time.
so here final speed v = 30 + 2*4 = 38 m/sec. answer
Distance travelled during this time
= (30 + 38) * 4 / 2 = 68 * 2 = 136 m answer
Answer:
A correlation coefficient represents the following:
1- The direction of the relationship
2- The strength of the relationship
Answer:
= 10.3 m/s
Explanation:
We can solve this exercise using the conservation of the moment; the system is formed by the knife and the target, with an isolated system the moment is conserved during the collision
Knife mass m = 22.5 g and its velocity v₁₀ = 39 m / s, the mass of white is M = 300 gr and its velocity is v₂₀ = -2.15 m / s
Before the crash
p₀ = m v₁₀ + M v₂₀
After the crash
= m v₁ₐ + 0
p₀ =
m v₁₀ + M v₂₀ = m
= (m v₁₀ + M v₂₀) / m
Let's calculate
= (0.0225 39.0 + 0.300 (-2.15)) / 0.0225
= 10.3 m / s
We have first velocity equals 8 m/s and the kinetic energy is 480 J
The order is the mass of the object
We have this formula K= mv2/2 isolating the mass we have m=k/v2
Now we will have m=480/8×8 > m= 480/64 m= 7.5kg now we deternimed the mass it's 7.5 kg