It confirmed medeleeve's hypothesis (prediction) and showed the use of his table
1. The property of a conductor by virtue of which it posses the flow of electric current through it is called resistance.
2. The resistance of a conductor depends on the cross sectional area of the conductor and it's resistivity.
3.This id due to the fact that the resistance of a wire is inversely proportional to the square of its diameter.
4.Due to at high temperatures , the alloy donot oxidize. Alloy doesn't melt readily and get deformed.
The frictional force is 39.4 N
Explanation:
We can solve this problem by applying Newton's 2nd law of motion: in fact, the net force acting on the block is equal to the product between its mass and its acceleration. So we can write
where
is the net force
m is the mass
a is the acceleration
Here we know that the box is moving with constant velocity, so its acceleration is zero:
This means that the net force is also zero:
The net force on the block is given by the applied force, forward, and the frictional force, backward:
where
is the applied force
is the frictional force
Therefore, solving for ,
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Answer:
a) 69.3 m/s
b) 18.84 s
Explanation:
Let the initial velocity = u
The vertical and horizontal components of the velocity is given by uᵧ and uₓ respectively
uᵧ = u sin 40° = 0.6428 u
uₓ = u cos 40° = 0.766 u
We're given that the horizontal distance travelled by the projectile rock (Range) = 1 km = 1000 m
The range of a projectile motion is given as
R = uₓt
where t = total time of flight
1000 = 0.766 ut
ut = 1305.5
The vertical distance travelled by the projectile rocks,
y = uᵧ t - (1/2)gt²
y = - 900 m (900 m below the crater's level)
-900 = 0.6428 ut - 4.9t²
Recall, ut = 1305.5
-900 = 0.6428(1305.5) - 4.9 t²
4.9t² = 839.1754 + 900
4.9t² = 1739.1754
t = 18.84 s
Recall again, ut = 1305.5
u = 1305.5/18.84 = 69.3 m/s
