Answer:
c.
Explanation:
Initial velocity of cheetah,u=1 m/s
Time taken by cheetah =4.8 s
Final velocity of cheetah,v=28 m/s
We have to find the acceleration of this cheetah.
We know that
Acceleration,
Where v=Final velocity of object
u=Initial velocity of object
t=Time taken by object
Using the formula
Then, we get
Acceleration, a=
Acceleration=
Hence, the acceleration of cheetah=
Answer:
Temperature of the gas molecules is 7.96 x 10⁴ K
Explanation:
Given :
Ions accelerated through voltage, V = 10.3 volts
The work done to change the position of singly charged gas ions is given by the relation :
W = q x V
Here q is charge of the ions and its value is 1.6 x 10⁻¹⁹ C.
Average kinetic energy of gas molecules is given by the relation:
K.E. =
Here T is temperature and k is Boltzmann constant and its value is 1.38 x 10⁻²³ J/K.
According to the problem, the average kinetic energy of gas is equal to the work done to move the singly charged ions, i.e. ,
K.E. = W
Rearrange the above equation in terms of T :
Substitute the suitable values in the above equation.
T = 7.96 x 10⁴ K