A ramp is often used to raise an object. If 80 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?

Tim's car breaks down just down the street from his house. he and his friends decide to try to push it to his house. using newton's three laws of motion, explain why this will be difficult.

A circular swimming pool has a diameter of 12 m. The circular side of the pool is 3 m high, and the depth of the water is 2.5 m. (The acceleration due to gravity is 9.8 m/s2m/s2 and the density of water is 1000 kg/m3kg/m3.

2. What other physical quantity might be more important to weightlifters than how much actual work they do?

What is the effective resistance of a car's starter motor when 150 A flows through it as the car battery applies 12.0 V to the motor?

A 60kg skateboarder starts up a 20° slope at 5m/s then falls and slides up the hill on his knee pads. The coefficient of kinetic friction between his knee pads and the ramp is 0.30. How far does he slide befor stopping?

What do radio waves and microwaves have in common? A. Both have shorter wavelengths than visible light. B. Both are located to the right of visible lights on the spectrum. C. Both have higher frequencies than visible light. D.

How long can you keep string cheese in the fridge?

A particular motor can provide a maximum torque of 110 n • m. assuming that all of this torque is used to accelerate a solid, uniform, cylindrical flywheel of mass 10.0 kg and radius 3.

Round your answers to one decimal place. This parallel circuit has two resistors at 15 and 40 ohms. What is the total resistance? Ω If there is a 12 V battery in the circuit, what would the approximate current be? A

Energy transfer by convection is usually restricted to what type of substance?