Question

A ramp is often used to raise an object. If 90 joules of energy are needed to lift an object to a platform but 100 joules are used in rolling the object up the ramp, what is the efficiency of the ramp?

Answer 1

90% efficentcy

Step-by-step explanation:

90 joules of energy were used to move the object, but 100 joules were supplied. There was a wasted 10 joules.

90/100 = .9 or 90%

Answer 2

Efficiency = 0.9 or 90%

Step-by-step explanation:

The amount of energy used in rolling the object up the ramp is 100 joules. This is the energy supplied to the object.

The amount of energy used to raise the object is 90 joules. This means the remaining 10 joules of energy is wasted in form of friction between the object and the ramp. Therefore, the useful energy utilized is only 90 J and remaining 10 J is wasted in the form of friction and heat.

Therefore, efficiency of the ramp is given as:

`\eta = \frac{\textrm{Energy utilized}}{\textrm{Energy supplied}}\\ \eta=(90\ J)/(100\ J)=0.9* 100= 90\%`

Therefore, the efficiency of the ramp is 90%.