Before you step on the brakes, the car has kinetic energy, when you step on the brakes, it turns the kinetic energy into heat (thermal energy). When it stops completely, it has potential energy. Hope this helped :)
C. High-visibility clothing is important to wear in areas with moving vehicles
Answer:
-0.5 m/s^2
Explanation:
Acceleration = change in velocity / total time
7.5 / 15 = 0.5
I do not recall the answer to this question
The only vertical forces are weight and normal force, and they balance since the surface is horizontal. The horizontal forces are the applied force (uppercase F) in the direction the block slides and the frictional force (lowercase f) in the opposite direction.
Apply Newton's 2nd Law in the horizontal direction:
ΣF = ma
F - f = ma
where f = µmg
F - µmg = ma
F = m(a +µg)
F = (20 kg)(1.4 m/s² + 0.28(9.8 m/s²)
F = 83 N
