The wavelength of yellow sodium light in air is 589 nm.

When a speeding truck hits a stationary car, the car is deformed and heat is generated. What can you say about the kinetic energ

cluponka [151]

nothing

Explanation:

we can say that it was certainly bad for the shopkeeper obviously and we should not be making questions about the physics behind that accident and should call the cops or 911

3 0

2 years ago

A 13,500 kg railroad freight car travels on a level track at a speed of 4.5 m/s. It collided and coupled with a 25,000 kg second

expeople1 [14]

Answer: 1.6m/s

Explanation:

M1 = 13500kg

U1 = 4.5m/s

M2 = 25000kg

U2 = 0m/s (since the body is at rest)

V = ? (Common velocity or velocity after impact)

M1U1 + M2U2 = (M1 + M2)V

But U2 = 0

M1U1 = (M1 + M2)V

13500 * 4.5 = (13500 + 25000)v

60750 = 38500v

V = 60750 / 38500 = 1.5779 = 1.6m/s

7 0

3 years ago

An object of mass m is initially at rest. After a force of magnitude F acts on it for a time T, the object has a speed v. Suppos

adell [148]

Answer:

It takes $\frac{1}{2}T$ to accelerate the object from rest to the speed v.

Explanation:

From Newton's second law:

$F=m\cdot a$ (1)

and the definition of acceleration,

$\displaystyle{a = \frac{\Delta v}{\Delta t}}$ (2)

we can solve this problem. Putting (2) in (1) we have:

$\displaystyle{F = m\cdot \frac{\Delta v}{\Delta t}}$ and solving for $\Delta t$ and considering the initial time as zero ( $t_0=0$ ) and the initial velocity also zero ( $v_0=0$ ) we have:

$\displaystyle{T=\frac{mv}{F}}$

Now, for a mass $m^*= 2m$ and the $F^*=4F$ we can wrtie the same equation:

$\displaystyle{T^*=\frac{m^*v}{F^*}}$ and substituting $m^*$ and $F^*$ :

$\displaystyle{T^*=\frac{2m\cdotv}{4F}=\frac{2}{4}T=\boxed{\frac{1}{2}T}}$

So now, it only takes half the time to accelerate the object from rest to the speed v

5 0

3 years ago

A man pushed a cabinet with a force of 200N. What is the mass of the cabinet that accelerates 4 m/s/s?

ELEN [110]

Answer:

$\boxed {\boxed {\sf 50 \ kg}}$

Explanation:

We are asked to find the mass of a cabinet, given the force and acceleration. According to Newton's Second Law of Motion, force is the product of mass and acceleration. The formula for this is:

$F= m \times a$

The force is 200 Newtons, but we should convert the units to make unit cancellation easier. 1 Newton is equal to 1 kilogram meter per second squared, so the force of 200 Newtons is 200 kilogram meters per second squared.

The mass is unknown and the acceleration is 4 meters per second per second or 4 meters per second squared.

F= 200 kg*m/s²
a= 4 m/s²

Substitute the values into the formula.

$200 \ kg *m/s^2 = m \times 4 \ m/s^2$

We are solving for the mass, m, so we must isolate the variable. It is being multiplied by 4 meters per second squared. The inverse operation of multiplication is division. Divide both sides by 4 m/s²

$\frac {200 \ kg *m/s^2}{4 \ m/s^2}= \frac{m \times 4\ m/s^2}{4 \ m/s^2}$

$\frac {200 \ kg *m/s^2}{4 \ m/s^2} =m$

The units of meters per second squared cancel.

$\frac {200 \ kg }{4 }=m$

$50 \ kg =m$

The mass of the cabinet is <u>50 kilograms.</u>

5 0

2 years ago

A car with speed v and an identical car with speed 2v both travel the same circular section of an unbanked road. If the friction

yawa3891 [41]

Answer:

$F'=\dfrac{F}{4}$

Explanation:

Let m is the mass of both cars. The first car is moving with speed v and the other car is moving with speed 2v. The only force acting on both cars is the centripetal force.

For faster car on the road,

$F=\dfrac{mv^2}{r}$