3. A ball thrown vertically upward returns to its starting point in 4s. Find its initial speed. [4]
1 answer:
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Answer:
The deformation is 0.088289 m
The final height of the monument is 170-0.088289 = 169.911702 m
Explanation:
Thermal coefficient of marble varies between (5.5 - 14.1) ×10⁻⁶/K = α
So, let us take the average value
(5.5+14.1)/2 = 9.8×10⁻⁶ /K
Change in temperature = 35-(-18) = 53 K = ΔT
Original length = 170 m = L
Linear thermal expansion
The deformation is 0.088289 m
The final height of the monument is 170-0.088289 = 169.911702 m (subtraction because of cooling)
(a) The force exerted by the electric field on the plastic sphere is equal to
where
is the charge of the sphere and E is the strength of the electric field. This force should balance the weight of the sphere:
where m is the mass of the sphere and g is the gravitational acceleration.
Since the two forces must be equal, we have:
and so we find the intensity of the electric field
(b) Now let's find the direction of the field. The electric force must balance the weight of the sphere, which is directed downward, so the electric force should be directed upward. Since the charge is negative, the force is opposite to the electric field direction, and so the direction of the electric field is downward.
where
where m is the mass of the sphere and g is the gravitational acceleration.
Since the two forces must be equal, we have:
and so we find the intensity of the electric field
(b) Now let's find the direction of the field. The electric force must balance the weight of the sphere, which is directed downward, so the electric force should be directed upward. Since the charge is negative, the force is opposite to the electric field direction, and so the direction of the electric field is downward.