All categories

2 years ago

A train on a straight track goes in the positive direction for 5.9 km, and then backs up for 3.8 km

Physics

1 answer:

kenny6666 [7]2 years ago

6 0

Answer:

2.1km

Explanation:

Ill take it as u are talking about the displacement

Since displacement has negatives and positves

5.9 - 3.8 = 2.1km

You might be interested in

A child of mass 40.0 kg is in a roller coaster car that travels in a loop of radius 7.00 m. at point a the speed of the car is 1

pav-90 [236]

I attached the missing picture.
The force of seat acting on the child is a reaction the force of child pressing down on the seat. This is the third Newton's law. The force of a child pressing down the seat and the force of the seat pushing up on the child are the same.
There two forces acting on the child. The first one is the gravitational force and the second one is centrifugal force. In this example, the force of gravity is always pulling down, but centrifugal force always acts away from the center of circular motion.
Part A
For point A we have:
$F_a=F_cf-F_g$
In this case, the forces are aligned, centrifugal is pointing up and gravitational is pulling down.
$F_a=m\frac{v^2}{r}-mg=179 $N$
Part B
At the point, B situation is a bit more complicated. In this case force of gravity and centrifugal force are not aligned. We have to look at y components of this forces, y-axis, in this case, is just pointing upward.
$F=F_{cf}\cos(30)-mg=m\frac{v^2}{r}\cos(30)-mg=153.2$N$
Part C
The child will stay in place at point A when centrifugal force and force of gravity are in balance:
$F_g=F_{cf}\\
mg=m\frac{v^2}{r}\\
gr=v^2\\
v=\sqrt{gr}=8.29\frac{m}{s}$

6 0

2 years ago

Two objects having masses m1 and m2 are connected to each other as shown in the figure and are released from rest. There is no f

tankabanditka [31]

Answer: $m_1g$

Explanation:

Given

Two masses $m_1$ and $m_2$ is released and there is tension T in the string

Suppose a is the acceleration of the system

Therefore from Diagram

For $m_1$

$T-m_1g=m_1a$

$T=m_1(g+a)$ ------1

for m_2 body

$m_2g-T=m_2a$

$T=m_2(g-a)$ -------2

From above two Equation it is said that Tension is greater than m_1g and less than m_2g

$m_1g$

4 0

2 years ago

Read 2 more answers

When a flat slab of transparent material is placed under water, the critical angle for light traveling from the slab into water

Novosadov [1.4K]

Answer:

(a) 40.6 degree

Explanation:

When refraction takes place from slab to water, the critical angle is 60 degree.

Use Snell's law

refractive index of water with respect to slab

$\mu _{w}^{s}=\frac{Sin60}{Sin90}$

$\frac{\mu _{w}}{\mu _{s}}=0.866$

$\frac{1.33}{\mu _{s}}=0.866$

μs = 1.536

Now for slab air interface, the critical angle is C.

$\mu _{a}^{s}=\frac{SinC}{Sin90}$

$\frac{\mu _{a}}{\mu _{s}}=\frac{SinC}{Sin90}$

1 / 1.536 = Sin C

C = 40.6 degree

3 0

2 years ago

A 310-km-long high-voltage transmission line 2.00 cm in diameter carries a steady current of 1,190 A. If the conductor is copper

Zolol [24]

Answer:

t = 141.55 years

Explanation:

As we know that the radius of the wire is

r = 2.00 cm

so crossectional area of the wire is given as

$A = \pi r^2$

$A = \pi(0.02)^2$

$A = 1.26 \times 10^{-3} m^2$

now we know the free charge density of wire as

$n = 8.50 \times 10^{28}$

so drift speed of the charge in wire is given as

$v_d = \frac{i}{neA}$

$v_d = \frac{1190}{(8.50 \times 10^{28})(1.6 \times 10^{-19})(1.26\times 10^{-3})}$

$v_d = 6.96 \times 10^{-5} m/s$

now the time taken to cover whole length of wire is given as

$t = \frac{L}{v_d}$

$t = \frac{310 \times 10^3}{6.96 \times 10^{-5}}$

$t = 4.46 \times 10^9 s$

$t = 141.55 years$

6 0

2 years ago

ul. The passengers standing on a stationary bus fall backward when the bus suddenly moves forward.Give reasons.

ipn [44]

The law of inertia states objects have a tendency to resist a change in motion. Given that, when the bus moved forward abruptly, the passengers had a natural tendency to resist the change in motion. Since they weren't moving before, they fell back because they had a tendency to stay in their state of equilibrium.

4 0

2 years ago