Answer:
Satellite D has a mass (kg) of 500 and the distance from Earth (km) is 320.
Explanation:
The universal law of gravitation states that the force between two objects in the universe is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
We have to choose the satellite having greatest gravitational force with earth. In all options the distance from the earth is same i.e. 320 km. So, we have to select the satellite having maximum mass because the mass of the earth is constant.
Hence, the correct option is (D) " Satellite D has a mass (kg) of 500 and the distance from Earth (km) is 320 ".
Answer:
1470kgm/s
Explanation:
Given parameters:
Mass of the rock = 50kg
Time taken for the free fall = 3s
Unknown:
Change in momentum = ?
Solution:
The change in momentum will be difference between the ending momentum and finishing momentum.
Momentum is the product of mass and velocity
Momentum = mass x velocity
Initial momentum = 0, the velocity is 0
Final momentum = mass x final velocity
let us find the final velocity;
V = U + gt
V is the final velocity
U is the initial velocity
g is the acceleration due to gravity = 9.8m/s²
t is the time
V = 0 + 9.8x3 = 29.4m/s
So;
Change in momentum = 50 x 29,4 = 1470kgm/s
The lens is used in adjusting the focus