Answer:
Time taken to travel remaining 228 miles = 2.4 hours.
Explanation:
Total distance = 876 miles.
Distance traveled after speed reduction = 228 miles
So, distance traveled before = 876 - 228 =648 miles.
Time taken for this = 6 hours.
Speed before speed reduction = 648/6 = 108 mph.
Speed after speed reduction = 108 - 13 = 95 mph
Time taken to travel remaining 228 miles = 228/95 = 2.4 hours.
Answer:
Explanation:
An impulse results in a change of momentum
If the wagon and dog both stop, they must have had equal and opposite momentums
FΔt = mΔv
F = mΔv/Δt = m(v₁ - v₀)/(t₁ - t₀)
v₁ = t₀ = 0
F = m(v₀)/t₁
F = 55(2.1)/0.1 = 1155 N
We could have also figured the dog's initial velocity and used the dog's mass in the equation as well. Result would be identical.
Answer:

Explanation:
From the exercise we know:




So, the average acceleration is:

The average force is:

Answer:
At 400 m the potential energy of the mountain climber doubled the initial value.
Explanation:
Given;
initial height of the mountain climber = 200 m
final height of the mountain climber, = 400 m
The potential energy of the mountain climber is calculated as;
Potential energy, P.E = mgh
At 200 m, P.E₁ = mg x 200 = 200mg
At 400 m, P.E₂ = mg x 400 = 400mg
Then, at 400 m, P.E₂ = 2 x 200mg = 2 x P.E₁
Therefore, at 400 m the potential energy of the mountain climber doubled the initial value.
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