Answer:
Walking burns up more energy,1740000J
Explanation:
Given that the displacement is 5.0km, and running at 10km/h and uses, walking at 3km/hr and uses 290watts:
Energy consumption for running is calculated as:
Energy consumption for walking is calculated as:
Walking is a slower process hence the need for more energy over longer periods raltive to running the same distance.
Hence walking burns more energy; 1,740,000J. It burns more because you walk for a greater period of time.
Answer:
The average velocity is 40km/h.
Explanation:
The average velocity is , where
is the distance traveled and
the time elapsed.
The distance traveled is clearly 80km since it's all done in the same direction, we only need to know the time elapsed. For this we calculate the time elapsed on the first part, and add it to the time elapsed on the second part using always the formula , where v is the velocity on each part, which is constant.
The time elapsed for the first part is , and the time elapsed for the second part is
, giving us a total time of
=2h.
Finally, we can calculate the average velocity: .
Answer:
a) v = 0.4799 m / s, b) K₀ = 1600.92 J, K_f = 5.46 J
Explanation:
a) How the two players collide this is a momentum conservation exercise. Let's define a system formed by the two players, so that the forces during the collision are internal and also the system is isolated, so the moment is conserved.
Initial instant. Before the crash
p₀ = m v₁ + M v₂
where m = 95 kg and his velocity is v₁ = -3.75 m / s, the other player's data is M = 111 kg with velocity v₂ = 4.10 m / s, we have selected the direction of this player as positive
Final moment. After the crash
p_f = (m + M) v
as the system is isolated, the moment is preserved
p₀ = p_f
m v₁ + M v₂ = (m + M) v
v =
let's calculate
v =
v = 0.4799 m / s
b) let's find the initial kinetic energy of the system
K₀ = ½ m v1 ^ 2 + ½ M v2 ^ 2
K₀ = ½ 95 3.75 ^ 2 + ½ 111 4.10 ^ 2
K₀ = 1600.92 J
the final kinetic energy
K_f = ½ (m + M) v ^ 2
k_f = ½ (95 + 111) 0.4799 ^ 2
K_f = 5.46 J