Your cousin is moving into an apartment in San Francisco. This apartment is on a street that is angled at 25∘ above the horizontal. He places a box of mass 15kg on the street. The coefficients of friction between the box and the street are μs=0.45 and μk=0.25.

A: He releases the box after he places it on the ground. Will it start to slide down the sloped road?
Yes or No?
B: As the box slides down the slope, what is its acceleration?
C: What is the magnitude of the minimum force he would have to apply to the box to keep it from sliding down the hill? Assume that he pushes parallel to the road and wants to hold it in place.
D: What is the magnitude of the minimum force he would have to apply to start pushing the box up the hill? Again assume that he pushes parallel to the road.

Jason and mia are both running in a race. as they approach the finish line, you being the physicist that you are decide to time how long it takes them to reach the end of the race. when you start your stop watch (you can take this as time t = 0 s) you notice that mia is an unknown distance d ahead of jason and both are moving with the same initial velocity v_0. you also notice that jason is accelerating at a constant rate of a_j, while mia is deaccelerating at a constant rate of -a_m. jason and mia meet each other for the first time at time t = t_1. at this time (t = t_1) jason's velocity is two times that of mia's velocity, meaning v_j (t_1) = 2v_m (t_1). a) draw the position vs. time graph describing mia's and jason's motion from time t = 0 to time t = t_1. clearly label your axes and initial conditions on your graph. b) draw the velocity vs. time graph describing mia and jason's motion from time t = 0s to time t = t_1. clearly label your axes and initial conditions on your graph. c) how long from when the stop watch was started at t = 0s did it take mia and jason to meet? express your answer in terms of know quantities v_0, a_m, and a_j. d) when the stop watch started at time t = 0s, how far apart, d, were mia and jason? express your answer in terms of know quantities v_0, a_m, and a_j.

Which type of wave can travel without a medium

While goofing off at the ice skating rink, a student takes off her shoes and places each of them on the ice. her friend, a hockey player, then shoots a hockey puck at each shoe. the first puck immediately comes to rest after it collides with the left shoe. the second puck rebounds after it collides with the right shoe. if each hockey puck has the same incoming speed, which shoe has greater speed after the collision? the right shoe. both shoes have the same speed. the left shoe.