The world’s largest gold bar, worth ten million dollars in 2014, has a base measuring 46 cm × 22 cm and exerts a pressure of 24 000 Pa on the surface it sits on.
a) Calculate the weight of the bar. Write your answer to two significant figures.
b) Calculate the mass of the bar. Write your answer to two significant figures.

a} 2400 N

b}240 kg

Explanation:

Pressure is force per unit area.

Given from the question that;

The pressure = 24000 Pa

Area = 0.46 * 0.22 =0.1012 m²

Calculating force from the formula;

P= F/A where P is pressure, F is force and A is area then

F= P*A = 24000*0.1012 = 2428.8 N

a) The weight is 2400 N  in 2 significant figures

b) Mass is calculated from the formula;

w= m* g  where w is weight, m is mass and g is acceleration due to gravity

2400 =  m * 9.81

m= 2400/ 9.81

m= 244.64

m= 240 kg { in 2 significant figures}

absorption lines are where light has been absorbed by the atom thus you see a dip in the spectrum whereas.

emission spectra have spikes in the spectra due to atoms releasing photons at those wavelengths.

explanation:

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.