Question

Кинетическая энергия тела равна 7,5 Дж., а его импульс - 5 кг/ м / с. Найдите массу и скорость тела.

Answer 1

Кинетическая энергия находится по формуле Е=(m*v*v)/2, где m-масса, v-скорость. Формула импульса тела p=m*v. Из первой формулы, так как есть значение Е получаем (m*v)*v=7,5*2=15 -> p*v=15 ->v=15/p

(так как р=5, то получаем:) v=3 м/с. m=p/v=5/3 кг.

Answer 2

$\left \{ {{E_{k}=\frac{mv^{2}}{2}} \atop {p=mv}} \right$

$\left \{ {{7,5=\frac{mv^{2}}{2}} \atop {5=mv}} \right$

$m=\frac{5}{v}$

$\frac{5*v^{2}}{v*2}=7,5$

$\frac{5v}{2}=7,5$

$v=3$м/с

$m=\frac{5}{3}=1\frac{2}{3}$кг

Answer 3

Calculation of Mass and Velocity

To find the mass and velocity of the object, we can use the equations for kinetic energy and momentum.

The equation for kinetic energy is:

KE = (1/2)mv^2 where KE is the kinetic energy, m is the mass, and v is the velocity of the object.

The equation for momentum is:

p = mv where p is the momentum, m is the mass, and v is the velocity of the object.

Given that the kinetic energy of the object is 7.5 J and the momentum is 5 kg·m/s, we can set up the following equations:

7.5 = (1/2)m*v^2 (Equation 1)

5 = m*v (Equation 2)

To solve for the mass and velocity, we can rearrange Equation 2 to solve for m:

m = 5/v (Equation 3)

Substituting Equation 3 into Equation 1, we get:

7.5 = (1/2)*(5/v)*v^2

Simplifying the equation:

7.5 = (5/2)*v

Solving for v:

v = (7.5*2)/5

v = 3 m/s

Substituting the value of v back into Equation 2 to solve for m:

5 = m*3

m = 5/3 kg

Therefore, the mass of the object is approximately 1.67 kg and the velocity is approximately 3 m/s.

Please note that these calculations assume no external forces acting on the object and that the object is moving in a straight line.