Question

Calculate the magnitude of the linear momentum for the following cases.

(a) a proton with mass 1.67  10^-27 kg, moving with a speed of 5.85  10⁶ m/s

 ___kg · m/s

(b) a 14.5-g bullet moving with a speed of 455 m/s

 ___kg · m/s

(c) a 74.0-kg sprinter running with a speed of 12.5 m/s

 ___kg · m/s

(d) the Earth (mass = 5.98  10²⁴ kg) moving with an orbital speed equal to 2.98  10⁴ m/s.

___ kg · m/s

Answer 1

(a) a proton with mass 1.67  10^-27 kg, moving with a speed of 5.85  10⁶ m/s:

$p=mv=(1.67\times 10^{-27}kg)( 5.85\times 10^6 \frac{m}{s})$

p = 9.7695 X 10^-21 kg · m/s

(b) a 14.5-g bullet moving with a speed of 455 m/s:

$p=mv=(14.5\times 10^{-3}kg)( 455 \frac{m}{s})$

p = 6.5975 kg · m/s

(c) a 74.0-kg sprinter running with a speed of 12.5 m/s:

$p=mv=(74\,kg)( 12.5\, \frac{m}{s})$

p = 925 kg · m/s

(d) the Earth (mass = 5.98  10²⁴ kg) moving with an orbital speed equal to 2.98  10⁴ m/s:

$p=mv=(5.98\times 10^{24}kg)( 2.98\times 10^4 \frac{m}{s})$

p = 1.78204 X 10²⁹ kg · m/s

Reference:

• Sears, F. W., & Zemansky, M. W. (1973). University physics.