Answer:
c. about 1/10 as great.
Explanation:
While jumping form a certain height when we bend our knees upon reaching the ground such that the time taken to come to complete rest is increased by 10 times then the impact force gets reduced to one-tenth of the initial value when we would not do so.
This is in accordance with the Newton's second law of motion which states that the rate of change in velocity is directly proportional to the force applied on the body.
Mathematically:


since mass is constant

when 
then,


the body will experience the tenth part of the maximum force.
where:
represents the rate of change in dependent quantity with respect to time
momentum
mass of the person jumping
velocity of the body while hitting the ground.
Answer:
T₂ = 95.56°C
Explanation:
The final resistance of a material after being heated is given by the relation:
R' = R(1 + αΔT)
where,
R' = Final Resistance = 207.4 Ω
R = Initial Resistance = 154.9 Ω
α = Temperature Coefficient of Resistance of Tungsten = 0.0045 °C⁻¹
ΔT = Change in Temperature = ?
Therefore,
207.4 Ω = 154.9 Ω[1 + (0.0045°C⁻¹)ΔT]
207.4 Ω/154.9 Ω = 1 + (0.0045°C⁻¹)ΔT
1.34 - 1 = (0.0045°C⁻¹)ΔT
ΔT = 0.34/0.0045°C⁻¹
ΔT = 75.56°C
but,
ΔT = Final Temperature - Initial Temperature
ΔT = T₂ - T₁ = T₂ - 20°C
T₂ - 20°C = 75.56°C
T₂ = 75.56°C + 20°C
<u>T₂ = 95.56°C</u>
Answer:
a)V=18.35 m/s (South -East)
b) t =7.41 m/s
c)D= 66.70 m
Explanation:
Given that
Velocity of boat in east direction = 16 m/s
Velocity of river = 9 m/s
a)The resultant velocity V

V=18.35 m/s (South -East)
b)
We know that
Distance = Velocity x time
Lets t time takes to cross the river
136 = 18.35 x t
t =7.41 m/s
c)
The distance covered downstream
We know that
Distance = Velocity x time
t= 7.41 s
D= 7.41 x 9 m
D= 66.70 m
The representation of this problem is shown in Figure 1. So our goal is to find the vector

. From the figure we know that:

From geometry, we know that:

Then using
vector decomposition into components:

Therefore:

So if you want to find out <span>
how far are you from your starting point you need to know the magnitude of the vector

, that is:
</span>

Finally, let's find the <span>
compass direction of a line connecting your starting point to your final position. What we are looking for here is an angle that is shown in Figure 2 which is an angle defined with respect to the positive x-axis. Therefore:
</span>
Answer:
delay or stifle the emergence of the perspective