A car is traveling 80km/h is 130m behind a truck traveling at 75km/h. How long will it take the car to reach the truck?

1 answer:

8 0

The car approaches the truck at a speed of 80-75=5km/h. To travel the 130m, it takes
$\frac{0.130km}{5 \frac{km}{h} } =0.026h=93.6s$

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A physicist comes across an open container which is filled with two liquids. Since the two liquids have different density, there

Dominik [7]

Answer:

496.57492 kg/m³

Explanation:

$P_a$ = Atmospheric pressure = 101300 Pa

$\rho_w$ = Density of water = 1000 kg/m^3

$h_w$ = Height of water = 21.8 cm

$h_f$ = Height of fluid = 30 cm

g = Acceleration due to gravity = 9.81 m/s²

$\rho_f$ = Density of the unknown fluid

Absolute pressure at the bottom

$P_{abs}=P_a+\rho_wgh_w+\rho_fgh_f\\\Rightarrow \rho_f=\frac{P_{abs}-P_a-\rho_wgh_w}{gh_f}\\\Rightarrow \rho_f=\frac{104900-101300-1000\times 9.81\times 0.218}{9.81\times 0.3}\\\Rightarrow \rho_f=496.57492\ kg/m^3$

The density of the unknown fluid is 496.57492 kg/m³

6 0

3 years ago

An electron passes through two rectangular regions that contain uniform magnetic fields, B1 and B2. The field B1 is stronger tha

gtnhenbr [62]

Answer:

v1 = v2

Explanation:

Given:

- The missing figure is (attached).

- The Magnetic Field B1 > B2

Find:

How does the speed v1 of the electron in region 1 compare with the speed v2 in region 2?

Solution:

- From Lorentz Law we know that the Force that acts on the charge particle is the cross product of Magnetic Field Vector ( B1 or B2 ) and the velocity vector (v1 or v1).

- From the attached figure related to this problem we see that the electron velocity or direction of motion is always parallel to the magnetic field B1&B2.

- The law of cross product for parallel vector is 0. Hence, the Lorentz force acting on the electron is also zero.

- Zero Force means no work is done on the particle by the magnetic field, thus, the change in kinetic energy also zero for conservation of energy to hold.

- The initial and final kinetic energies of the electron is same. Hence, we can conclude that v1 = v2.