A road slopes upward so that it climbs 2 m for each 10 m of distance along the r

Question

A road slopes upward so that it climbs 2 m for each 10 m of distance along the road. A car whose weight is 8 kN moves up the road at a constant speed of 20 m/s. Determine the minimum power. A 2 kg mass has potential energy of 2 J when it is how high above the ground? A 2 N weight has potential energy of 2 J when it is how high above the ground? Find the height of a 100 kg object if 5000 J was expended in lifting the object. A 5 kg mass has kinetic energy of 2.5 Joules. What's the speed of the object? A 5 N weight has kinetic energy of 2.5 Joules. What's the speed of the object? Car A has a mass of 500 kg and a speed of 90 km/hr. Car B has a mass of 1500 kg and a speed of 30 km/hr. What is the kinetic energy of car A relative to car B? Find the kinetic energy of a 1500 kg car moving at 90 km/hr. Find the speed of a 1500 kg car that has kinetic energy of 400 kJ. The height above the ground of a child on a swing varies from 75 cm at the lowest point to 150 cm at the highest point. Find the maximum speed of the child. The 3 kg head of an ax is moving at 40 m/s when it strikes a log. If the blade of the ax penetrates 15 mm into the log, find the average force the ax exerts on the log. The car of a roller coaster starts from rest 20 m above a reference level. If there is no friction or air resistance, find the car's speed 10 m above the reference level. Find the car's speed 15 m above the reference level. Find the car's speed at the reference level. Find the car's speed 25 m above the reference level.

Explanation / Answer

Potential energy E = mgh

Where

m – mass of the object

g – Acceleration due to gravity

h – height of the object

51)

E =mgh

2 = 2x9.8xh

h = 0.1020 m

52)

E = mgh

Weight w = mg = 2

2 = 2h

h = 1 m

53)

Energy spent in lifting will be stored as potential energy

5000 = 100x9.8xh

h = 5.10 m

54)

Kinetic energy KE = ½ mv2

V is velocity and m is the mass

2.5 = 5v2/2

V = 1 m/s

55) w = mg = 5 N

m x 9.8 = 5

m = 0.5102 kg

Kinetic energy KE = ½ mv2

2.5 = 0.5102 x v2/2

V2 = 9.8

V= 3.13 m/s

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.