Answer:
83,900 J
Explanation:
First, find the acceleration:
F = ma
1150 N = (1600 kg) a
a = 0.719 m/s²
Now find the final velocity.
Given:
Δx = 45.8 m
v₀ = 6.25 m/s
a = 0.719 m/s²
Find: v
v² = v₀² + 2aΔx
v² = (6.25 m/s)² + 2 (0.719 m/s²) (45.8 m)
v = 10.2 m/s
Now find the final KE:
KE = ½ mv²
KE = ½ (1600 kg) (10.2 m/s)²
KE = 83,920 J
Rounded to three significant figures, the final kinetic energy is 83,900 J.
It decreases because it gave its momentum to the other car.
Answer:
(a) Most reactive 
Metal B
Metal D
Metal A
Least reactive Metal C
(b) (i) Bubbles should form very slowly
(ii) No reaction takes place
Explanation:
(a) The given metals arranged in their order of reactivity are;
Most reactive Metal B
Metal D
Metal A
Least reactive Metal C
The other of reactivity is based on the nature of their reactivity of the metals in air
(b) (i) Based on the reactivity of the metals in air, whereby metal A reacts very slowly and an oxide is formed, we have that, based on the reactivity of the metal A, when mixed with dilute hydrochloric acid, bubbles should form very slowly
(ii) Similarly, given that metal C is unreactive, we have that when small pieces of metal C are added to dilute hydrochloric acid, no reaction takes place.
If an object's velocity is steadily increasing it means that the acceleration is constant at a certain value.
Choice A shows an acceleration of zero which would only be true if the object was not moving or if its velocity was not changing.
Choice B gives us a graph showing acceleration increasing over time and is therefore incorrect.
Choice C is correct because the acceleration is constant. Steadily increasing tells us that the acceleration is fixed at a certain value.
Choice D is incorrect an represents a constant negative acceleration. This would be the case if the object was steadily decreasing in velocity.
