Answer:
Car A has twice the energy of car B.
Explanation:
The kinetic energy of an object is given by :
Where
m is the mass
v is the speed of the object
Car A has twice the mass of Car B. Both travel at the same speed i.e.
So,
So, the kinetic energy of car A is twice of the kinetic energy of car B.
Complete question:
The recoil of a shotgun can be significant. Suppose a 3.6-kg shotgun is held tightly by an arm and shoulder with a combined mass of 15.0 kg. When the gun fires a projectile with a mass of 0.040 kg and a speed of 380 m/s, what is the recoil velocity of the shotgun and arm–shoulder combination?
Answer:
The recoil velocity of the shotgun and arm–shoulder combination is 1.013 m/s
Explanation:
Given;
combined mass of the shotgun and arm–shoulder, m₁ = 15 kg
mass of the projectile, m₂ = 0.04 kg
speed of the projectile, u₂ = 380 m/s
let the recoil velocity of the shotgun and arm–shoulder combination = u₁
Apply the principle of conservation of linear momentum;
m₁u₁ + m₂u₂ = 0
m₁u₁ = - m₂u₂
Therefore, the recoil velocity of the shotgun and arm–shoulder combination is 1.013 m/s