A 1000-kg barge is being towed by means of two horizontal cables. one cable is pulling with a force of 80.0 n in a direction 30.
1 answer:
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Answer:
Induced emf,
Explanation:
We have,
Number of turns in the coil, N = 40
Radius of coil, r = 3 cm = 0.03 m
The field increases from 0 to 0.75 T at a constant rate in a time interval of 225 s.
It is required to find the magnitude of the induced emf in the coil if the field is perpendicular to the plane of the coil. The induced emf is given by :
, is magnetic flux
So, the magnitude of induced emf is .
a) 2.64 s
We can solve this part of the problem by using the following SUVAT equation:
where
s is the displacement of the stone
u is the initial velocity
t is the time
a is the acceleration
We must be careful to the signs of s, u and a. Taking upward as positive direction, we have:
- s (displacement) negative, since it is downward: so s = -75.0 m
- u (initial velocity) positive, since it is upward: +15.5 m/s
- a (acceleration) negative, since it is downward: so a= g = -9.8 m/s^2 (acceleration of gravity)
Substituting into the equation,
Solving the equation, we have two solutions: t = -5.80 s and t = 2.84 s. Since the negative solution has no physical meaning, the stone reaches the bottom of the cliff 2.64 s later.
b) 10.4 m/s
The speed of the stone when it reaches the bottom of the cliff can be calculated by using the equation:
where again, we must be careful to the signs of the various quantities:
- u (initial velocity) positive, since it is upward: +15.5 m/s
- a (acceleration) negative, since it is downward: so a = g = -9.8 m/s^2
Substituting t = 2.64 s, we find the final velocity of the stone:
where the negative sign means that the velocity is downward: so the speed is 10.4 m/s.
c) 4.11 s
In this case, we can use again the equation:
where
s is the displacement of the package
u is the initial velocity
t is the time
a is the acceleration
We have:
s = -105 m (vertical displacement of the package, downward so negative)
u = +5.40 m/s (initial velocity of the package, which is the same as the helicopter, upward so positive)
a = g = -9.8 m/s^2
Substituting into the equation,
Which gives two solutions: t = -5.21 s and t = 4.11 s. Again, we discard the first solution since it is negative, so the package reaches the ground after
t = 4.11 seconds.
Answer:
cal
Explanation:
= mass of ice = 100 g = 0.1 kg
= specific heat of ice = 0.5 cal/(kg°C)
= specific heat of water = 1 cal/(kg°C)
= Latent heat of fusion of ice = 80 J/g
= initial temperature of ice = - 20 °C
= final temperature of ice = 50 °C
Q = Heat gained
Heat gained is given as
cal