Answer:
194,400 joules of kinetic energy.
Explanation:
Remember that to calculate the Kinetic energy you need to use the next formula:

We know that Mass= 1200 kg and velocity is 18m/s, so we insert those values into the formula:

So the kinetic energy of a car moving at 18m/s with a mass of 1200 kg would be 194,400 joules.
Answer:
1.045 m from 120 kg
Explanation:
m1 = 120 kg
m2 = 420 kg
m = 51 kg
d = 3 m
Let m is placed at a distance y from 120 kg so that the net force on 51 kg is zero.
By use of the gravitational force
Force on m due to m1 is equal to the force on m due to m2.



3 - y = 1.87 y
3 = 2.87 y
y = 1.045 m
Thus, the net force on 51 kg is zero if it is placed at a distance of 1.045 m from 120 kg.
15 km 30 divided by 4 is 7.5 km in 30 min times that by 2 the answer is 15
Answer:
The speed of the shell at launch and 5.4 s after the launch is 13.38 m/s it is moving towards the Earth.
Explanation:
Let u is the initial speed of the launch. Using first equation of motion as :

a=-g

The velocity of the shell at launch and 5.4 s after the launch is given by :

So, the speed of the shell at launch and 5.4 s after the launch is 13.38 m/s it is moving towards the Earth.