какое количество теплоты нужно передать льду массой 100г , при температуре -0 градусов чтобы расплавить

A dad takes his kids to their school just 8.0 miles down the road but with traffic it takes him 30 minutes and the fastest he ca

VARVARA [1.3K]

Answer:C 24 mi/hr

Explanation:

8 0

3 years ago

A body of mass 2.7 kg makes an elastic collision with another body at rest and continues to move in the original direction but w

kramer

Answer:

a)

1.35 kg

b)

2.67 ms⁻¹

Explanation:

a)

$m_{1}$ = mass of first body = 2.7 kg

$m_{2}$ = mass of second body = ?

$v_{1i}$ = initial velocity of the first body before collision = $v$

$v_{2i}$ = initial velocity of the second body before collision = 0 m/s

$v_{1f}$ = final velocity of the first body after collision =

using conservation of momentum equation

$m_{1} v_{1i} + m_{2} v_{2i} = m_{1} v_{1f} + m_{2} v_{2f}\\(2.7) v + m_{2} (0) = (2.7) (\frac{v}{3} ) + m_{2} v_{2f}\\(2.7) (\frac{2v}{3} ) = m_{2} v_{2f}\\v_{2f} = \frac{1.8v}{m_{2}}$

Using conservation of kinetic energy

$m_{1} v_{1i}^{2}+ m_{2} v_{2i}^{2} = m_{1} v_{1f}^{2} + m_{2} v_{2f}^{2} \\(2.7) v^{2} + m_{2} (0)^{2} = (2.7) (\frac{v}{3} )^{2} + m_{2} (\frac{1.8v}{m_{2}})^{2} \\(2.7) = (0.3) + \frac{3.24}{m_{2}}\\m_{2} = 1.35$

b)

$m_{1}$ = mass of first body = 2.7 kg

$m_{2}$ = mass of second body = 1.35 kg

$v_{1i}$ = initial velocity of the first body before collision = 4 ms⁻¹

$v_{2i}$ = initial velocity of the second body before collision = 0 m/s

Speed of the center of mass of two-body system is given as

$v_{cm} = \frac{(m_{1} v_{1i} + m_{2} v_{2i})}{(m_{1} + m_{2})}\\v_{cm} = \frac{((2.7) (4) + (1.35) (0))}{(2.7 + 1.35)}\\\\v_{cm} = 2.67$ ms⁻¹

8 0

3 years ago

Which statement is correct about the potential energy of a car moving down a ramp?

Paha777 [63]

Potential energy is highest when the car is released at the top of the ramp. The correct answer is option C

Potential energy is the energy possessed by a body when the body is at rest. Potential energy is at time called gravitational potential energy which as a product of mass of the body, acceleration due to gravity and the height attained by the body. That is,

P.E = mgh

When a car is moving down a ramp, the potential energy of the car can never remain the same except the car stop at a certain point.

Whenever a car is moving down a ramp, the potential energy of the car will be highest when the car is release at the top of the ramp. And lowest when the car reaches the bottom of the ramp.

The statement that is correct about the potential energy of a car moving down a ramp is:

Potential energy is highest when the car is released at the top of the ramp.

Therefore, the correct answer is option C

Learn more here: brainly.com/question/17400615

8 0

2 years ago

Winding roads are made on hills, why?

FromTheMoon [43]

Answer.

The road on the hills goes upward with the increasing length of the road.That's why we make a winding roads because it reduces the allover surface inclination in every portion of the road which is suitable for driving the vehicles.

3 0

3 years ago

What happens when a proton is brought near another proton?

muminat

They will repel each other because they both have positive charges.

5 0

3 years ago