Question

Определите показания динамометра,если подвешенный на нём стальной брусок объёмом 50 см³ опустить в ккеросин.(Плотность керосина 800 кг/м³,стали 7800 кг/м³)

Answer 1

P=mg-Fa =p1vg-p2gv=gv(p1-p2) =10*50*10^-6(7800-800)=5*10^-4*7*10^3=3,5 H

Answer 2

Determining the Readings of a Dynamometer

To determine the readings of a dynamometer when a steel block with a volume of 50 cm³ is suspended from it and immersed in kerosene, we can use the principles of buoyancy and Archimedes' principle.

Step 1: Calculate the Buoyant Force The buoyant force can be calculated using the formula: \[ F_b = \rho_{\text{kerosene}} \times g \times V_{\text{displaced}} \] Where: - \( \rho_{\text{kerosene}} = 800 \, \text{kg/m}^3 \) (density of kerosene) - \( g = 9.81 \, \text{m/s}^2 \) (acceleration due to gravity) - \( V_{\text{displaced}} = 50 \, \text{cm}^3 = 50 \times 10^{-6} \, \text{m}^3 \) (volume of the steel block)

Calculating the buoyant force: \[ F_b = 800 \times 9.81 \times 50 \times 10^{-6} \]

Step 2: Calculate the Weight of the Steel Block The weight of the steel block can be calculated using the formula: \[ W = m \times g \] Where: - \( \rho_{\text{steel}} = 7800 \, \text{kg/m}^3 \) (density of steel) - \( V_{\text{steel}} = 50 \, \text{cm}^3 = 50 \times 10^{-6} \, \text{m}^3 \) (volume of the steel block) - \( m = \rho_{\text{steel}} \times V_{\text{steel}} \)

Calculating the weight of the steel block: \[ W = 7800 \times 9.81 \times 50 \times 10^{-6} \]

Step 3: Determine the Readings of the Dynamometer The readings of the dynamometer can be determined by comparing the buoyant force and the weight of the steel block. The dynamometer will show a reading equal to the difference between the buoyant force and the weight of the steel block.

\[ \text{Dynamometer Reading} = F_b - W \]

By calculating the values of \( F_b \) and \( W \), we can determine the readings of the dynamometer when the steel block is immersed in kerosene.

Please note that the actual readings may vary based on the precision of the measurements and the accuracy of the equipment used.