Aspace probe on the surface of mars sends a radio signal back to earth, a distance of 7.19 ×10⁷ km. radio travel at the speed of light (3.00 ×10⁸ m/s). how many seconds does it take for the signal to reach the earth?

240 seconds

Explanation:

Data Given:

Distance Radio travel to earth = 7.19 ×10⁷ km

Speed of this radio signal = 3.00 ×10⁸ m/s

Solution:

First convert Km to m

1 km = 1000 m

7.19 ×10⁷ km = 7.19 ×10⁷ x 1000 = 7.19 × 10¹⁰m

Formula used to calculate time

            Speed (S) = distance (d) / time (t)

rearrange above equation for time

            time (t) = distance (d) / Speed (S) . . . . . . . . .(1)

Put values in equation 1

            time (t) = 7.19 × 10¹⁰/ 3.00 ×10⁸ m/s

            time (t) = 240 s

So 240 seconds it take for the signal to reach the earth

the objects have the same charge.

weight of any object is given by

w = m*g

where m is mass of the object and g is the acceleration due to gravity.

for earth the value of g is 9.8 m/s^2 so

w=117.6 n m=12 g=?

117.6=12g => g=9.8 m/s^2

which is the force of gravity on earth.