Billy Sue is speeding down a country road in his new monster truck at a constant 32 m/s when he goes over a hill and spots a cow standing in the middle of the road. The cow is 45m in front of him. If he reacts immediately upon viewing the cow, and his braking acceleration is 20 m/s 2 , can he stop in time to avoid hitting the cow?

He won't stop on time, the distance his car traveled during the braking is greater than 45 m.

Explanation:

Given;

initial velocity of Billy's car, u = 32 m/s

his braking acceleration, -a = 20 m/s

his final velocity when the car stops, v = 0

Apply the following kinematic equation to determine the distance traveled by Billy's car during the braking acceleration;

v² = u² + 2as

0 = 32² + (2 x -9.8)s

0 = 32² - 19.6s

19.6s = 32²

s = (32²) / (19.6)

s = 52.25 m

The distance traveled is greater than 45 m, thus Billy's car will hit the cow.

scientific laws are the result of testing theories and proving them to be facts.

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards