Answer:
65.3
Explanation:
W = (1/2)mv^2
W = (1/2)(0.145kg)(30m/s)^2
Answer:
F = 13.08 N
Explanation:
given,
mass of spreader = 10.9 Kg
angle made with angle = 45.3°
accelerate the spreader to 1.35 m/s in 1.6 s.
Acceleration = ![\dfrac{v}{t}](https://tex.z-dn.net/?f=%5Cdfrac%7Bv%7D%7Bt%7D)
= ![\dfrac{1.35}{1.6}](https://tex.z-dn.net/?f=%5Cdfrac%7B1.35%7D%7B1.6%7D)
= 0.844 m/s²
momentum in = momentum out
F × t = m × v
![F cos \theta \times t = m \times v](https://tex.z-dn.net/?f=F%20cos%20%5Ctheta%20%5Ctimes%20t%20%3D%20m%20%5Ctimes%20v)
![F cos \ 45.3^0 \times 1.6 = 10.9 \times 1.35](https://tex.z-dn.net/?f=F%20cos%20%5C%2045.3%5E0%20%5Ctimes%201.6%20%3D%2010.9%20%5Ctimes%201.35)
F×1.125 = 14.175
![F = \dfrac{14.175}{1.125}](https://tex.z-dn.net/?f=F%20%3D%20%5Cdfrac%7B14.175%7D%7B1.125%7D)
F = 13.08 N
hence, the force applied by the joe is equal to F = 13.08 N
Answer: The softer barrier is the better option
Explanation:
1) When is a car is moving at a certain speed, it has a certain amount of momentum (p=mv). A collision against a barrier would cause its momentum to decrease to 0. A change in momentum is Impulse
2) The formula for Impulse: J = f * Δt
J is Impulse
f is the force applied during the time Δt
A tough barrier would produce a smaller Δt, which means more force is applied on the car. (J is always constant)
A softer barrier would apply less force on the car, which means Δt is large.
Answer: The softer barrier is the better option