I can't help if u don't write the full question
weight of 30 Kg object= 300 N
Explanation:
Weight= m I
m= mass=30 kg
I= gravitational filed strength= 10 N/kg
weight=30 (10)
weight=300 N
Petroleum products are especially useful as sources of energy because it furnishes a convenient, concentrated source of energy.
In physics, it is convenient that there are already derived formulas for rectilinear motion at constant acceleration from Newton's Law of motion. One of these equations useful for this problem is:
2ax = vf2 - v02, where a is the acceleration, x is the distance, vf is the final velocity and v0 is the initial velocity.
Now, a=-8 ft/s2. It is negative because the car is decelerating. The distance x is 100 ft, the vf is equal to 0m/s because the car comes to a stop. The only unknown would be v0.
2(-8 ft/s2)(100 ft) = (0m/s)^2 - v0^2
v0 = 40 m/s