HELP PLZZ BEST ANSWER WILL GET MARKED BRANILYEST!! (sorry cant spell)

Physics

2 answers:

sergey [27]3 years ago

4 0

based on the table calcium-47 is the correct answer

guajiro [1.7K]3 years ago

3 0

Calcium 47 is best suited as a radioactive tracer for the body's use of calcium

You might be interested in

A rocket is launched straight up from the earth's surface at a speed of 1.80×104 m/s .part awhat is its speed when it is very fa

balandron [24]

We can solve the problem by using the law of conservation of energy.

When the rocket starts its motion from the Earth surface, its mechanical energy is sum of kinetic energy and gravitational potential energy:
$E_i = K_i + U_i = \frac{1}{2} m v_i^2 + (- \frac{GM}{r} )$
where
m is the rocket's mass
$v_i = 1.8 \cdot 10^4 m/s$ is the rocket initial speed
$G=6.67 \cdot 10^{-11} m^3 kg^{-1} s^{-2}$ is the gravitational constant
$M=5.97 \cdot 10^{24} kg$ is the Earth's mass
$r= 6.37 \cdot 10^6 m$ is the distance of the rocket from the Earth's center (so, it corresponds to the Earth's radius)

The mechanical energy of the rocket when it is very far from the Earth is just kinetic energy (because the gravitational potential at infinite distance from Earth is taken to be zero):
$E_f = K_f = \frac{1}{2} mv_f ^2$
where $v_f$ is the final speed of the rocket.

By equalizing the initial energy and the final energy, we can find the final velocity:
$\frac{1}{2} mv_i ^2 - \frac{GM}{r} = \frac{1}{2}m v_f^2$
$v_f = \sqrt{v_i^2 - \frac{GM}{r} } =1.41 \cdot 10^4 m/s$

3 0

4 years ago

Read 2 more answers

The energy expenditure value of traveling by car is 3.6 mj/passenger-kilometer. The value for traveling by train is 1.1 mj/passe

andrezito [222]

Answer:

Using lighter material in car construction, improving energy efficiency by enhancing engine design or replacing the engine with more efficient technologies.

Explanation:

Using lighter materials in the car construction, reducing the potential energy required to accelerate and to move the car, as well as energy losses due to rolling friction. There is evidence of such benefits by replacing steel and aluminium parts with components made of composite materials.

Improving the design of internal combustion engines to minimize energy losses and accordingly, improving energy efficiency. A more radical approach is replacing internal combustion engines with electric engines, which offer higher efficiencies. Such conclusions can be easily inferred from model based on Work-Energy Theorem and Principle of Energy Conservation:

$\eta_{engine} \cdot U_{engine} = \frac{1}{2} \cdot m_{car} \cdot v^{2} + \mu_{r} \cdot m_{car} \cdot g \cdot \Delta s$