Which two issues have increased the need for alternatives to fossil fuels?

A 10 n net force is applied to an object, which then accelerates at 4 m/s2. what is the mass of the object?

Which of the following properties of light can only be explained by wave theory and not by the Photoelectric effect? reflection refraction interference velocity

A wave has a wavelength of 4 m and a frequency of 85 Hz. What is the speed of this wave?

Calculate the resistance of the filament of a 40 Watt lightbulb if it draws 3 amperes when 120V are impressed across it

Jeff is listening to the radio. He knows that the radio produces sound energy because A. he can hear music coming from the radio. B. he can feel heat coming from the back of the radio. C. he can see the display on the radio when it lights up. D.

Which statement is NOT true? Light travels with or without a medium Light travels faster than sound Sound must have a medium to travel through Both light and sound must have a medium to travel through

When light bends as it enters a different medium the process is known as what?

Work out the kinetic energy of a 2.5 kg remote-controlled car that is moving at 2 m/s.

Suppose a block moves across a rough horizontal surface at constant speed under the action of a horizontal 3-N force. Which statement concerning this situation is not true? a. There is more than the 3-N horizontal force acting on the block. b.

A m = 2.45 kg object hangs in equilibrium at the end of a rope (taken as massless) while a wind pushes the object with a F W = 18.9 N horizontal force. Find the magnitude of the tension in the rope and the rope's angle from the vertical.