Explanation:
The heart rate of the astronaut is 78.5 beats per minute, which means that the time between heart beats is 0.0127 min. This will be the time t measured by the moving observer. The time t' measured by the stationary Earth-based observer is given by

a) If the astronaut is moving at 0.480c, the time t' is


This means that time between his heart beats as measured by Earth-based observer is 0.0145 min, which is equivalent to 69.1 beats per minute.
b) At v = 0.940c, the time t' is


So at this speed, the astronaut's heart rate is 1/(0.0372 min) or 26.9 beats per minute.
Answer:
Explanation:The four closest to the sun — Mercury, Venus, Earth and Mars — are the terrestrial planets. They have rocky surfaces enclosed by relatively shallow atmospheres.
No they are not the same material because having the same density doesnt mean its the same material also they can have a different density and be the same material
Answer:
He traveled 9km
Explanation:
To do this problem you need to use the equation which is Speed= distance/time and this problem gives you the speed which is 18 km/h and it gives you the time 1/2 hour so you write the equation 18= d/ 1/2 which his distance is 9km
p=F/A
or,P=d×V×G/A (m=d×V)
or,p= d× A×h×g/A (A and A are cut)
or,P=d×H×G