Explanation:
It is given that,
Mass of platinum bar, m = 750 g
Length of the bar, l = 5 cm
Breadth of the bar, b = 4 cm
Width of the bar, h = 1.5 cm
Volume of the bar, 

We need to find the density of the platinum bar. The density of any substance is given by :



So, the density of the platinum bar
. Hence, this is the required solution.
Answer:
Atomic number of the daughter isotope = (Atomic number of the parent isotope) - 4
Explanation:
An alpha particle has atomic number of 2 and a mass number of 4
Losing two alpha particles would lead to a reduction of 4 in atomic number and 8 in mass number for the radioactive isotope, to give the stable daughter isotope.
We are asked to solve for the frequency heard when a car is coming towards the observer. The car is moving at 16 m/s and the velocity of the sound is 343 m/s where the car horns at 583 Hz. We will use Doppler's Effect formula in calculating the unknown frequency such that the solution is shown below:
Fl = (V + Vl) * Fs / (V - Vs)
FL = (343 + 0)*583 / (343 - 16)
FL = 611. 53 Hertz
The answer for the frequency of the observer is 611.53 hertz.
Well, the spring constant is measured using the F=k∆x, where F is the force, k is the constant, and ∆x is the change in position. So if the mass is 1.98, the force (mxg) is 19.4. Thus the spring constant is 19.4/.0478(change in position). This equals 405.86.
Answer:
Lindsey biked 45 miles for 3 hours at 15 mph and walked 8 miles for 2 hours at 4 mph.
Explanation:
Speed = distance/time
Let the distance that Lindsey biked through be x miles and the time it took her to bike through that distance be t hours
Then, the rest of the distance that she walked is (53 - x) miles
And the time she spent walking that distance = (5 - t) hours
Her biking speed = 15 mph = 15 miles/hour
Speed = distance/time
15 = x/t
x = 15 t (eqn 1)
Her walking speed = 4 mph = 4 miles/hour
4 = (53 - x)/(5 - t)
53 - x = 4 (5 - t)
53 - x = 20 - 4t (eqn 2)
Substitute for X in (eqn 2)
53 - 15t = 20 - 4t
15t - 4t = 53 - 20
11t = 33
t = 3 hours
x = 15t = 15 × 3 = 45 miles.
(53 - x) = 53 - 45 = 8 miles
(5 - t) = 5 - 3 = 2 hours
So, it becomes evident that Lindsey biked 45 miles for 3 hours at 15 mph and walked 8 miles for 2 hours at 4 mph.