Answer:
L2 = 1.1994 m
the length of the pendulum rod when the temperature drops to 0.0°C is 1.1994 m
Explanation:
Given;
Initial length L1 = 1.2m
Initial temperature T1 = 27°C
Final temperature T2 = 0.0°C
Linear expansion coefficient of brass x = 1.9 × 10^-5 /°C
The change i length ∆L;
∆L = L2 - L1
L2 = L1 + ∆L ...........1
∆L = xL1(∆T)
∆L = xL1(T2 - T1) ......2
Substituting the given values into equation 2;
∆L = 1.9 × 10^-5 /°C × 1.2m × (0 - 27)
∆L = 1.9 × 10^-5 /°C × 1.2m × (- 27)
∆L = -6.156 × 10^-4 m
From equation 1;
L2 = L1 + ∆L
Substituting the values;
L2 = 1.2 m + (- 6.156 × 10^-4 m)
L2 = 1.2 m - 6.156 × 10^-4 m
L2 = 1.1993844 m
L2 = 1.1994 m
the length of the pendulum rod when the temperature drops to 0.0°C is 1.1994 m
<h2>
Power of cheetah is 5576.85 W = 7.48 hp</h2>
Explanation:
Power is the ratio of energy to time.
Here we need to consider kinetic energy,
Mass, m = 102 kg
Initial velocity = 0 m/s
Final velocity = 16.2 m/s
Time, t = 2.4 s
Initial kinetic energy = 0.5 x Mass x Initial velocity² = 0.5 x 102 x 0² = 0 J
Final kinetic energy = 0.5 x Mass x Final velocity² = 0.5 x 102 x 16.2² = 13384.44 J
Change in energy = Final kinetic energy - Initial kinetic energy
Change in energy = 13384.44 - 0
Change in energy = 13384.44 J
Power = 13384.44 ÷ 2.4 = 5576.85 W = 7.48 hp
Power of cheetah is 5576.85 W = 7.48 hp
I think you're fishing for "temporary magnet" or something like that,
but I don't agree with it.
Credit card strips, refrigerator magnets, recording tape, bar magnets,
and big heavy horseshoe magnets are permanent magnets ... you don't
have to keep an electric current circulating around them to make them
magnetic.
But that doesn't mean that they stay magnetic no matter WHAT you do
to them. They can be DEmagnetized by being heated, dropped on the
floor, hit with a hammer, or in the presence of another, stronger magnet.
