Aramp 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?

Efficiency = 0.9 or 90%

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:

Therefore, the efficiency of the ramp is 90%.

yup its correct its: c) b b

a

explanation:

no diagram was provided, but i'm guessing it's the one i've attached to my answer.

here, a mechanical force turns the rod.   this generates an electric current in the coil, which powers the bulb.