A wood block sits on an angled concrete ramp. A person stands at the bottom of the ramp and pushes on the block so that a non-zero force is applied parallel to the angled surface of the ramp. Assume that we can neglect air resistance. For this scenario, which of the following statements about friction is false? A. If the block is moving, then the force due to friction is independent of how hard the person is pushing.
B. The force due to friction depends on the mass of the block, regardless of whether the block is moving or stationary.
C. If the block is not moving, then the force due to friction depends on how hard the person is pushing.
D. If the block is not moving, then the force due to friction must be zero.
E. The force due to friction depends on the angle of the ramp, regardless of whether it is moving or stationary

Aprojectile is launched horizontally 10m above the ground and with an initial velocity of 15 m/s. a) determine the magnitude and direction of projectile velocity at t= 1.3s b) determine the magnitude and direction of projectile acceleration at t=1.3s

Search coils and credit cards. one practical way to measure magnetic field strength uses a small, closely wound coil called a search coil. the coil is initially held with its plane perpendicular to a magnetic field. the coil is then either quickly rotated a quarter-turn about a diameter or quickly pulled out of the field. (a) derive the equation relating the total charge q that flows through a search coil to the magnetic-field magnitude b. the search coil has n turns, each with area a, and the flux through the coil is decreased from its initial maximum value to zero in a time ∆t. the resistance of the coil is r, and the total charge is q = i∆t, where i is the average current induced by the change in flux. (b) in a credit card reader, the magnetic strip on the back of a credit card is rapidly “swiped” past a coil within the reader. explain, using the same ideas that underlie the operation of a search coil, how the reader can decode the information stored in the pattern of magnetization on the strip. (c) is it necessary that the credit card be “swiped” through the reader at exactly the right speed? why or why not?

Cathy is pedaling down a steep hill on her bicycle and wants to be able to coast up the next hill, which is 25 meters high, without pedaling. cathy and her bicycle have a mass of 75 kg. assuming her bicycle is 100% efficient, what would her speed have to be?